A few important things to think about when selecting a tire:
Tread wear rating (UTQG): the higher the number the longer the tire will last, 100 is the standard, a 200 rating will last twice as long as a 100, ect. Typically, higher UTQG ratings are harder tires and will be less dependable in low tempratures, slippery surfaces, and may have non-uniform traction changes during tread wear (tires get less grippy as they wear out).
Traction: Government stuff, pretty broad; AA is best, A is good, B is decent, ect. Has to do with breaking distance only.
Heat rating: A is good, B is decent, ect... if you like to cruise at high speed for prolonged periods of time, get A and be done with it. Tire failure ain't cool yo!
Tire Weight: Tire rack is one of the few places that actually list tire weights, remember that rotational mass is muiltiplied the further away from the center of rotation you get... so having a heavy tire will suck away horsepower, torque, and gas milage. If you save 2lbs by getting a particular tire, you save 8lbs of rotating mass all over.
The tires you buy should match your driving style at its maximum... if you like to push the car, get the best tires. If you just doddle around town and get your foot into it only when there's plenty of room for error, then by all means get a decent tire. For the amount of times my Michelins have saved my ass, they were worth every penny. I recommend looking for tires that gradually lose traction at their limits, rather than ones that just suddenly let go.