I lived there for a summer, bit I was in the Pigeon Forge, Sevierville, Gatlinburg area and didn't spend a ton of time in Knoxville proper.  The 3 towns I named are just tourist traps, so you can find a lot to do while you drove through.
I remember bungee jumping at Wild Woodys as well, they have a big wooden go kart track that was fun too.  The aquarium in Gatlinburg was a fun stop as well.