I will second Kirby Lane and the Drafthouse. I don't know what they are calling Mr. Sinus Theater these days, but I used to love those shows.
Bitter End Brewery is a little high end on the price range, but the beer and food are good. Saltlick BBQ if you can get a ride out there.
Breakfast tacos from Rudy's are good (BBQ is pretty good as well at any of them).
If you want a good record store, check out Waterloo Records. Bookpeople across the street is a pretty great bookstore as well. Austin Books is a pretty great comic book store.
Freebirds has great burritos (the one at Hancock Center is also frequented by many UT Co-eds).
Check out what is at the Harry Ransom Center at UT. They have some great exhibits there (the Ransom Center actually has one of the original Letherface masks from Texas Chainsaw Massacre).
And as someone said, check to see if the Paramount is playing anything. They have great old movies during the summer.