currently- Zero Tolerance #0200.
previously- Buck/Strider Tarini, Benchmade AFCK with Ti liners, Spiderco Endura (tore the threaded inserts for the clip out of the handle when i snagged it on something. still works as a knife, but now it stays in the toolbox as a backup knife) Spyderco Delica with the integral clip (that got lost when i had to go back to the ticket counter and check it in a box i'd flown from Vegas to LA with it, but the LA metal detectors ere a little more sensitive, this was long before 9-11) a CRKT Desert Cruiser which was nice but too bulky for pocket carry) and an absolute POS Sifu from REKAT (carried that ONE DAY before it started to fall apart)
and various SAKs before the trend of one handed opening knives with pocket clips and locking blades took off.