OMG, where to start!! Just moved here from Milwaukee area in November, and to think I was worried I'd get bored with only mexican to eat - little did I know the variety of mexican (and everything else).
Tacodeli! - The mole tacos, adobados, and fontera fundido tacos all rule and their dona sauce is amazing. I would kill to know how to make this sauce at home!!! The breakfast tacos (migas and Jess special are my favs) go great with it too.
Magnolia Cafe - Only been to the south location. Gingerbread pancakes that rule, fish tacos that are pimpin', my wife and kids have tried several other things on the menu as well. Great for breakfast too - eat outside if it's nice out.
Homeslice - True brooklyn style pizza on South Congress. Nuff said.
Thai Kitchen - Off of Bee Caves rd. west of MoPac. Hole in the wall vibe inside but awesome food.
Thundercloud subs - Elvis shakes rule. I love the Texas tuna sandwhich as well.
Sarovar - Indian off of Burnett. Buffet style but they have something for everyone, and fairly affordable too.
Amy's Ice Cream - Their pumpkin tastes so accurate you'd think they grow the pumpkins in a cone

. Tons of true-to-ingredients flavors.
Thunderbird burritos - Think a way, way better version of Qdoba if you've eaten there. Never had BBQ sauce go so well with a burrito.
Trudy's - Great tex-mex - I'm especially fond of their migas.
I could go on forever. But those are some favorites.