Vita sale now on in PS Store. PS Plus is also great value now it includes Vita.
I love all these:
Pinball Arcade (cross-buy - buy for PS3 and get for Vita as well) - I bought a Vita to play this.
Super Stardust Delta
Lumines Electronic Symphony - I am addicted to this on the PSP, PS3 and Vita.
Rayman Origins - great platformer
Little Big Planet Vita - there is a cross-platform DLC to play with people on a PS3 that is also great fun.
When Vikings Attack (cross-buy - my kids love this)
I have Uncharted and Gravity Rush free from PS Plus. They are both good games, but not my style. Oddworld Stranger's Wrath HD is ok. BlazBlue is fun if you like Tekken/Street Fighter etc.
Need for Speed Most Wanted is ok, but reminds me of Burnout Legends and Dominator on the PSP too much.
FIFA Football is a blast, if you like sport games.
Other downloadables, on the cheaper end, that are worth a look (some of these might be free or have recently been free on PS Plus):
- Mutant Blobs Attack
- Big Sky Infinity
- Motor Storm RC
- Sine Mora
- Knytt Underground
thers is a stack of old PSP games that play on the Vita as well. Street Fighter Alpha 3 Max; Capcom Classics Collection Reloaded; Patapon 2 etc.
Been also playing a bit of Playstation All-Stars Battle Royale - the Vita version is free if you buy the PS3 version (but not vice-versa).
I love the Vita. My 3DS barely gets a look-in any more.