Marko has written a paean to his everyday carry pocketknife.
I, too, am a little baffled when I run into people who don't carry a knife. I mean, what do they use when they need to open something? Their teeth?
I still haven't gotten around to sending my Emerson Commander back to the maker for a tune-up (one of the tiny screws that hold the scales on went missing and the liner lock was starting to show some wear,) so for the past several years I'm most likely to be found carrying a Benchmade Stryker. It's big and sturdy enough to handle most any chore to which you'd set a pocketknife without being too bulky in the pocket, and the ATS-34 blade takes a wicked edge.
The biggest downside is that it's too big to fit in the pockets of my Gap jeans which have shallow girlie pockets more for decoration than for actually carrying anything, so on the days I wear those, I carry a smaller knife, usually a CRKT Urban Shark or a Spyderco Dodo, both of which are sadly discontinued. (Both also sport blade lengths compliant with even Chicago's anal knife laws.)