PS Vita has loads of RPGs. This pic has some of the best.

Danganronpa
Persona 4 Golden
Trails in the sky (this is actually a psp game but you can get it for vita on the psn store)
Disgaea 3
Disgaea 4

Tales of Hearts R (Action RPG)
Y's (Action RPG)
Demon Gaze (Dungeon RPG)
FF X/ X-2 HD (RPG)
Freedom Wars (Hunting)
Toukiden (Hunting) *wait for Kiwami
Corpse Party (Visual Novel)
Mind Zero (Dungeon RPG)
Zero Escape (Visual Novel)
Danganronpa (Visual Novel)
Trails in the sky (RPG)
Brandish the dark revenant (Dungeon Action RPG)

There are a lot RPG's on the Vita dude! This are the bests:
Soul Sacrifice 
Toukiden: The Age of Demons
Freedom Wars
Tales of Hearts R
Final Fantasy X / X2 HD Remaster
Persona 4: Golden
DanganRonpa: Goodbye Despair
Ys: Memories of Celceta

Purchasing a Vita was probably one of the better decisions you could have made. Best handheld hardware out there.

P4G
YS
Sen No Kiseki(If u understand Japanese/Chinese)

I think but idk.  I do know all Disgaea games are on there though.  And pretty much every PSP game that ive looked for on there is.  Hope that helps.

What ill say about the Vita is that its actually a very good device regardless of what people say about it.  I have more games for my Vita than 3DS actually.  It may not be supported with super popular blockbusters all the time, but it still has some very good games.  

I own this on PSN anyway, and it is a fantastic game. I also just discovered Tactics Ogre. So fepic.

I am definitely not regretting my decision.