Vita was amasing if you like Disgaea.

PSP games:
Disgaea 1: Afternoon of Darkness (best version)
Disgaea 2: Dark Hero Days (best version)
Disgaea Infinite, Prinny: Can I Really Be The Hero?
Prinny 2: Dawn of Operation Panties, Dood!
+
Vita games:
Disgaea 3: Absence of Detention (best version)
Disgaea 4: A Promise Revisited (best version)

Its just lacking Disgaea 5...

On the topic of what Vita was good for, how about those Final Fantasy titles?

Final Fantasy Origins (I&II)

Final Fantasy III (PSP port of the DS remake)

Final Fantasy IV: Complete Edition (FFIV and FFIV: The After Years)

Final Fantasy VI

Final Fantasy VII

Final Fantasy VIII

Final Fantasy IX

Final Fantasy

Final Fantasy X-2

Final Fantasy Tactics (Both OG for PS1 and War of the Lions for PSP)

Dissidia Final Fantasy

Dissidia 012 Final Fantasy (And Prologus, but that's more of a demo)

World of Final Fantasy

That's 15 titles if you don't count Prologus and the double helping of Tactics, and also not counting the three XIII titles available via PlayStation Now.