General

@Spidy78: Please take your time to read my entire post if you're serious about using my $1k build.

[quote=spidy78]How much do you think it's gonna weight once I fully assemble it?[/quote]
Since it's a micro-ATX build and not a standard ATX one, the fully built rig from my $1k list would weigh ~20lbs.
The case has 2 big, flexible, but sturdy handles for shock absorption so you shouldn't have to worry about carrying it.

[quote=spidy78]Also , is it easy to assemble , as I haver never assembled any pcs.[/quote]
It requires some learning, but that should put off only the extremely lazy as you can learn it in less than 1 hour.
[url=https://www.youtube.com/watch?v=vbDiSMQ_L_k]Popular tutorial 1[/url]
[url=https://www.youtube.com/watch?v=XsyxM_j3Y4U]Popular tutorial 2[/url]
One note of caution is that you should always be static-free before you touch your PC components to build (especially your CPU and mobo). Meaning that you shouldn't build on top of a carpet, and always touch something metal for like 2 seconds before you start or resume building. If not, you can potentially kill your parts and you're out a couple hundred bucks.
Just build on a hardwood floor/desk and you're fine.
Btw, do you need a wifi-card? Or are you going to have a wired Ethernet connection? If it's the former, you need to add a wifi-card or a USB wifi-adapter, which costs like $20~30.

[quote=spidy78]By the way,if I were to build the one you suggested, what monitor do you think I should get ?[/quote]
I'll need to give you some important information, as idk what your needs are yet:

There are two popular types of monitors: TN and IPS.
1) [url=https://www.youtube.com/watch?v=DWXcNlh85Ps]TN panels have terrible viewing angles compared to IPS panels as shown from 0:30-0:55 here[/url]. However, they have extremely low input lag, meaning that the monitor can show each image frame from a game faster, which helps in any FPS, racing, and competitive e-Sports games.
2) IPS panels have great viewing angles and color accuracy, so if you play games where photo-realism is a big factor (like RPGs), or if you do some photo/video editing, IPS is the way to go.
Me personally, I don't really see the difference in the lower input-lag of a TN monitor compared to an IPS monitor. Unless you plan to play lots of FPS/racing games in multiplayer, just stick to an IPS.

Then there's the resolution to talk about. The de facto standard for PC gaming these days is 1920x1080, or 1080p. If you choose to game at 1080p, my $1k build for you will be able to play even the most demanding titles at 60fps with completely maxed out Ultra settings.
a) [url=http://www.amazon.com/ASUS-VS239H-P-23-Inch-Full-HD-Monitor/dp/B008DWITHI?tag=amazon0606-20]Here's a popular 1080p IPS monitor.[/url]
b) [url=http://www.amazon.com/BenQ-GL2460HM-24-Inch-LED-Lit-Monitor/dp/B00IKDFL4O]Here's a popular 1080p TN monitor.[/url]
Both cost ~$150 each.

But since the graphics card I included in my $1k build for you is a GTX 970, you can also consider buying a 2560x1440 (or 1440p) monitor. You won't be able to max out the graphics of every demanding game out there at 1440p with a GTX 970, but you can still get pretty close with some settings turned down from Ultra to Very High or High.
c) [url=http://www.amazon.com/Acer-G257HU-smidpx-25-Inch-Widescreen/dp/B00QS0AKVK?tag=amazon0606-20]Here is a popular 1440p IPS monitor. It also costs $100 more @ $250[/url]
*All 3 monitor links [url=http://www.144hzmonitors.com/gaming-monitors-buyers-guide-august-2015]at the courtesy of this website[/url]

[quote=hyperfire7][url=http://www.newegg.com/Product/Product.aspx?Item=N82E16834232404]This is a pretty decent $1k gaming laptop[/url]
1) The GTX 960M laptop graphics card in that laptop is [url=http://www.notebookcheck.net/NVIDIA-GeForce-GTX-960M.138006.0.html]about the same to a GTX 480 desktop graphics card in performance[/url], meaning that you'll be able to play even modern, demanding AAA titles like The Witcher 3 and the like at low to medium settings @ 1080p with enjoyable frame rates.
2) The laptop I recommended comes with a 1TB Hard Drive instead of an SSD though. While there is an option to upgrade to a 128GB SSD, you have to pay $200 extra which is not worth the money. Rather I advise you to buy your own SSD like this [url=http://www.amazon.com/Samsung-2-5-Inch-Internal-MZ-75E250B-AM/dp/B00OAJ412U]250GB Samsung 850 EVO for $100[/url] and replace the hard drive with that SSD yourself [url=http://rog.asus.com/376092014/g-series-gaming-laptops/g551-upgrade-guide/]by following this easy guide[/url].
Including tax, buying that laptop and the SSD will net you around $1,200.

However, I must really advise you against gaming laptops. You can build a gaming PC that can kick even the most demanding titles to the curb at max settings at 1080p, and for cheaper.
Since portability is a huge concern for you, [url=http://pcpartpicker.com/p/7f22CJ]here is a $1k build that with built in a portable-friendly case.[/url]
You can find out more about that particular case here: https://www.youtube.com/watch?v=eTzKZZp48lM
If you want to spend all of your $1.2k budget, you can get a GTX 980 graphics card instead of the 970 and that'll be able to max out many games even at 1440p.[/quote]

How much do you think it's gonna weight once I fully assemble it ? Also , is it easy to assemble , as I haver never assembled any pcs. By the way,if I were to build the one you suggested , what monitor do you think I should get ?

Definitely get that gaming pc. Dollar for dollar, you'll get more performance out of a gaming pc than you will from a laptop. Not only that, you have options with a pc whereas laptops are a locked down system. Let's say you want to upgrade your graphics card in 2-3 years to play the latest games in the future. You could easily upgrade your pc by swapping out with a new graphics card or even buying a used card and doing a SLI/crossfire configuration. But you can't upgrade a gaming laptop in most cases and would likely need to buy a new gaming laptop 2-3 years from now if you wanted something with enough performance for the latest games.

[quote=aznanimality]+1 this guy knows his stuff.
However, I disagree with the gtx 480 running The Witcher 3 on Medium.[/quote]
Notice how I said low to medium.

[quote=aznanimality]I'm on a gtx 770 and I can barely run it at high. And I have Nvidia Hairworks off. 24GB Ram, 4670k OCed to 4.2 [/quote]
1) Maybe you got unlucky and purchased an underperforming GTX 770.
2) Performance impact on different graphical settings for Witcher 3 doesn't seem to affect the FPS much except shadow and foliage density settings. Leave those on high, have hairworks turned off, but make everything else ultra and you should be getting 45~50fps @ 1080p, as that's what I get with my GTX 770, i5-4670k @ 4 GHz and 8 GB RAM rig.

[quote=hyperfire7][url=http://www.newegg.com/Product/Product.aspx?Item=N82E16834232404]This is a pretty decent $1k gaming laptop[/url]
1) The GTX 960M laptop graphics card in that laptop is [url=http://www.notebookcheck.net/NVIDIA-GeForce-GTX-960M.138006.0.html]about the same to a GTX 480 desktop graphics card in performance[/url], meaning that you'll be able to play even modern, demanding AAA titles like The Witcher 3 and the like at low to medium settings @ 1080p with enjoyable frame rates.
2) The laptop I recommended comes with a 1TB Hard Drive instead of an SSD though. While there is an option to upgrade to a 128GB SSD, you have to pay $200 extra which is not worth the money. Rather I advise you to buy your own SSD like this [url=http://www.amazon.com/Samsung-2-5-Inch-Internal-MZ-75E250B-AM/dp/B00OAJ412U]250GB Samsung 850 EVO for $100[/url] and replace the hard drive with that SSD yourself [url=http://rog.asus.com/376092014/g-series-gaming-laptops/g551-upgrade-guide/]by following this easy guide[/url].
Including tax, buying that laptop and the SSD will net you around $1,200.

However, I must really advise you against gaming laptops. You can build a gaming PC that can kick even the most demanding titles to the curb at max settings at 1080p, and for cheaper.
Since portability is a huge concern for you, [url=http://pcpartpicker.com/p/7f22CJ]here is a $1k build that with built in a portable-friendly case.[/url]
You can find out more about that particular case here: https://www.youtube.com/watch?v=eTzKZZp48lM
If you want to spend all of your $1.2k budget, you can get a GTX 980 graphics card instead of the 970 and that'll be able to max out many games even at 1440p.[/quote]

+1 this guy knows his stuff.
However, I disagree with the gtx 480 running The Witcher 3 on Medium.
I'm on a gtx 770 and I can barely run it at high. And I have Nvidia Hairworks off. 24GB Ram, 4670k OCed to 4.2
OP You should definitely use that money and build what this guy has made for you, greatest bang for your buck.
However he IS missing the Windows 7/8 Operating system which costs ~100$ but there are ways around that.

[quote=spidy78]After hearing everyone's responses and because of how I move a lot right now , I decided to follow this idea.
Can anyone suggest a mediocre gaming laptop ?[/quote]
[url=http://www.newegg.com/Product/Product.aspx?Item=N82E16834232404]This is a pretty decent $1k gaming laptop[/url]
1) The GTX 960M laptop graphics card in that laptop is [url=http://www.notebookcheck.net/NVIDIA-GeForce-GTX-960M.138006.0.html]about the same to a GTX 480 desktop graphics card in performance[/url], meaning that you'll be able to play even modern, demanding AAA titles like The Witcher 3 and the like at low to medium settings @ 1080p with enjoyable frame rates.
2) The laptop I recommended comes with a 1TB Hard Drive instead of an SSD though. While there is an option to upgrade to a 128GB SSD, you have to pay $200 extra which is not worth the money. Rather I advise you to buy your own SSD like this [url=http://www.amazon.com/Samsung-2-5-Inch-Internal-MZ-75E250B-AM/dp/B00OAJ412U]250GB Samsung 850 EVO for $100[/url] and replace the hard drive with that SSD yourself [url=http://rog.asus.com/376092014/g-series-gaming-laptops/g551-upgrade-guide/]by following this easy guide[/url].
Including tax, buying that laptop and the SSD will net you around $1,200.

However, I must really advise you against gaming laptops. You can build a gaming PC that can kick even the most demanding titles to the curb at max settings at 1080p, and for cheaper.
Since portability is a huge concern for you, [url=http://pcpartpicker.com/p/7f22CJ]here is a $1k build with a portable-friendly case.[/url]
You can find out more about that particular case here: https://www.youtube.com/watch?v=eTzKZZp48lM
If you want to spend all of your $1.2k budget, you can get a GTX 980 graphics card instead of the 970 and that'll be able to max out many games even at 1440p.

[quote=thiefy996]It might get ya an okay to decent gaming laptop, but it probably won't last ya that long. Best bet would probably be a heavy duty gaming computer for when ya're at home and a mediocre laptop for gaming on the go.[/quote]
After hearing everyone's responses and because of how I move a lot right now , I decided to follow this idea.
Can anyone suggest a mediocre gaming laptop ?

Laptops will never outperform computers. If you need to bring a computer with you at least once a month, go for a laptop. Other than that, desktop will kill the laptop in all other categories. I personally like laptops more because I myself take my computer to wherever I go so its practical. The specs of a $1200 laptop can very easily be 500-900 dollars in a desktop depending on how smart you shop for parts, your area, etc. For me, I would personally build my own desktop because my cousin has his own computer company so I can just scavenge off the parts, but its not practical for me to have a desktop. If you feel the need to move around a computer more than 2-3 times a year, definitely opt for a laptop

My friend bought a $2000 gaming laptop and my $1200 desktop is much better. He recently got a desktop and said it's a much better decision.

gaming laptops are weak af, they usualy run half the ghz on the proc and over heat much more quickly that a gaming pc. Basically 0 air circulation.

You could try building a microITX computer. I don't have experience with them, but from what I can tell, they are very portable, but if you're using the computer for classes, I'd just go with a laptop.

I would personally go for a Desktop PC.

Portability vs speed lol. Those are the two factors to take in.

what serious gamer even play games on laptops
17 screen vs dual 24/27's and max graphic settings

A good gaming laptop goes for 1450-1700+. But all laptops are ticking time bombs when you game often on them. I would recommend a gaming pc unless you're like me and at that point in your life where you're moving a lot, then it might be more convenient to just get a gaming laptop.

I'd personally go with a PC cause I love the feeling of fully customizable and being able to change parts if one fails, or if you stumble across extra spending money and want to get a quick upgrade like extra RAM or something.