Usually a Camillus Cuda: ATS-134, liner lock, sliding thumb post opener, 4" blade. Sometimes, a Camillus EDC: 154CM, frame lock, 3" blade.
Around $100 if I recall right. It's discontinued but you might be able to find someplace online that still has them. There are a lot of great knives out there by many makers. Just get one with good steel and if you're getting a folder, get one with a strong lock (frame lock is my preference).
Currently lusting for a Benchmade Griptillian, but until then, here are my regulars: Kershaw Blur, the "little tag cutter," which is always in my pocket My CRKT Desert Cruiser can be found in an outside pocket of my purse for emergncy use. It's good at getting hinges off doors. When the mood strikes me, I'll carry one or more of these, too: CRKT Tactical Tanto, although that thigh sheath is a pain Ka-Bar TDI Law Enforcement Knife And occassionally my Cold Steel Peace Keeper II
