Lately I've been carrying a Spyderco ManBug VG-10. I like the VG10 blades, they hold a nice edge. Most of my EDC knife duty involves opening letters and boxes, so I like something small that fits in that little 5th pocket of my jeans. The ManBug works like a charm and can be opened one-handed. I love it.
Outdoor Edge Slidewinder. Outstanding little cutter blade knife. I backpocket carry mine with a short rawhide lanyard in lieu of a clip. A quick and convenient one-hander when I need it. Less than $15, too.
Victorinox Swiss Army. Almost too small, 2.5 inches at most, but is lightweight and has some neat gadgets, like a toothpick and tweezer. The two blades are a bit flimsy, but have never failed what I wanted them to do. So light and small, you forget it is in your pocket. I have a large thick one which has a corkscrew, file, punch, mini scissors and other tools beside three blades. But it is too thick and bulky for a pocket knife. When I do carry the large one, it is in a pouch on my belt. Both of these knives are old friends of mine. Every man should own at least one Swiss Army knife.