General

Crit damage, arguable crit rate if not maxed.
The holy three:

Damage
PDR
Boss Damage

and status resistance (NOT ELEMENTAL RESISTANCE!!)
as for how many points - up to you to divide it in the way you see fit

So, I'm lv230 and this is what I have so far:

Level 10 Critical Damage
Level 9 Ignore Defense
Level 10 Damage
Level 10 Boss Damage
Level 7 Status Resistance

I plan to max Ignore Def & Status Resistance by 250. If there's any left, I'll do Ele Attacks.

I dind't put any points in hyper skill stats yet because i'm afraid that i would screw it up so i hope you could help me, thank you.

I'll c&p what I've added/decided to add in future, in the morning.

Crit Damage & Total Damage are probably the best, although the rest really depends on your gear. Got low Pdr? Increase Pdr. Low Boss? Increase boss %