Kershaw is the only choice, IMO. Depending on your definition of cheap, like others said.
They probably have a decent quality (for the price, I would say 'excellent quality') knife that suits you for somewhere in the 20-40 buck range. They generally don't have slop, they hold up well (and easy to fix/adjust if they do have issues), the blades are decent steel, and they're the 'original' assisted open with a dead-simple spring system.
edit:
http://www.academy.com/webapp/wcs/s...l&N=0&storeId=10151&langId=-1&catalogId=10051
Top two results are both great. I've had a Chive for ages. The Leek is a little bigger, if desired.
The Tone is too 'tacticool' for some, but the handles are a nice material, and the blade is very good steel. I like tanto blades for their ability to function as an improvised 'x-acto' knife. And it also works as a hammer; chunky bastard.