The bigger difference you'll notice is between membrane and mechanical keyboards.
Membrane keyboards have a rubber mat under the keys that fire off the keystrokes, they're generally pretty quiet and for the most part fairly popular among PC users.
Mechanical keyboards use physical switches under each key and are fairly noisy since they make a definite click when you press them. More favored by enthusiasts and gamers. Notable manufacturers of mechanical boards are Razer (Black Widow series) and Steelseries. I've heard good things about both. This is my keyboard
Overall I'm pretty happy with it but I'm really starting to miss the 10 key as a programmer. I might look into getting a Black Widow Ultimate, I wish I could find someone to trade with