Mine varies quite a lot. When I have any kind of knife in my pocket, it's usually a Spyderco or SAK. However, I live in a city, and work on a college campus, so I end up leaving the pocket knife at home a lot of the time, knowing the way people freak out about knives in the city.
When I'm doing my normal work day, I always carry a backpack with my laptop and some gear, and I usually have a slightly larger but still EDC sized fixed blade knife in there. Lately that's been a Swamp Rat Vex made from D2, which I picked up at BLADE. I was hoping to win one of those sweet little HEST's at the show, but I didn't get lucky.