Here's my opinions on a few of the titles:
Guilty Gear Xrd -Revelator- : Amazing prices for this. If you like fighters, grab it. No-brainer. Gorgeous graphics, the best fighting tutorial I've ever seen, and a good amount of stuff to unlock.
Digimon Story Cyber Sleuth: Looks amazing on Vita. Runs slightly better on PS4. Great, long, monster-collecting RPG with a story that gets better as it goes along. No prior Digimon knowledge required to fully enjoy this.
Tales of Zestiria: Not the best Tales game, but still pretty good. I love the characters, the world and story are alright, and the combat and leveling systems are unique... Not a bad price for this at all if you know what you're going into or just want a decent JRPG.
Tales of Symphonia Chronicles: One classic Tales game that is pretty good and its sequel which is widely regarded as atrocious. Can't beat the price though.
Omega Quintet: Utter trash. I normally can enjoy subpar games with moe pandering, but this was just all-around terrible. Avoid.
Akiba's Trip: Fun game with a unique combat system. Some heavy anime and moe pandering here, but if you can look past it or enjoy it you'll like this, especially for the price.
Catherine: Total cult classic. It's a weird sort of puzzle/climber that can get pretty challenging
Senran Kagura: Bon Appetit: Definitely not the best rhythm game on Vita, but it's decent. You get the Hanzo and Hebijo girls with the game, but the other two schools are DLC only and it never goes on sale so if you want the full experience it'll be an additional $15.
Senran Kagura: Shinovi Versus: The combat is a lot of fun and sort of like a musou game. A huge cast of great characters. If you enjoy/can overlook the pandering stuff it's a really great game.
Mamorukun Curse!: Cheap little bullet hell. I really enjoyed it. Lots of replayability and high scores to achieve.
One Piece Pirate Warriors 3: Easily one of the best Musou games out there. No One Piece knowledge required for enjoyment. LOTS of content at a low price. No-brainer if you enjoy musou.
Superbeat: Xonic: Really fantastic rhythm game, probably the best on the system. Lots of EDM/Techno/Pop. Grab it if you're into music games at all.