I have several.
Scamp - gave a bunch of these out to friends one Christmas. Cheap, but decent keychain lockback for people without knives.
Speed Demon (clip pt.) - unfortunate name, but good smaller lockback to toss in a briefcase or drop in a pocket (I keep it in my camcorder case). Locks up good, gets sharp
Bolt action - smoooth knife. Smooth action, bead blast flat ground drop point, great lock system, lo-profile clip. My car-console knife.
Speedster - nice larger lockback. The too-curved handle makes it a little un-ergonamic, but it is a strong locker, nice opening hole, good blade shape, and thick blade stock. Tip-up carry (what I prefer). Reversible clip (clip grabs too tight, though). I have the ATS-34 model, but I've been thinking of getting the AUS model from SMKW. Even with AUS steel, a great buy at $12.99.
I've been thinking of getting the Buddy System too. I like to pin a knife inside my trunks for swimming at the beach, and I'm not 100% confident in the sheath on the CS Ready-Edge that I currently use. For "inside the swim trunks", you want to make sure your sheath holds the blade!