Battle Heart -- awesome. (It's the game your D&D game was based on.)
Infinity Blade -- free (IB2 is out, so IB went free. It's a deal!)
Kingdom Rush -- great game ($1) but hard, I'd wait for it to go free.
Nimble Quest -- free, strange, fun
Bit Dungeon, Card Quest -- both dungeon explore games.
My latest fav is Block Fortress which I got on sale for $1 but is probably $2 now.
If you're really into gaming, grab the Touch Arcade app (free) and take a look at http://appshopper.com/ . re: Appshopper app, so if you have it installed that's great -- if not, you can't dload it right now b/c Apple said "no" to them for now.
Other apps: Evernote, Dropbox, Tapforms, Flipboard, Yelp, Sol, EasyFTP, Craigslist +, Kickstarter, GasBuddy, Imo, Waze, Blogger, Blogger +, iBart, Ancestry
Pics: PS Express, Adobe ideas, Bokeh Lens, ComicBook, Nostalgio, Orange Cam, Photostudio,
TV: Netflix, HBO Go, Youtube, TED
Music: TuneIn Radio, SoundHound, SoundCloud, Pacifica, Pandora, Downcast, Figure, Animoog, Loopy, RandGrid, DM1, 5-0 Radio