I'm very happy with Vredestein Spiders - 1.8" nominal width, with the centre inch slick and knobbles on the outside. At full pressure the knobbles don't touch tarmac unless you lean the bike over on corners, so they're reasonably fast, yet the tread is there for gravel tracks and dirt. I wouldn't want to use them in really muddy condition, but they seem fine on gravel or dirt for nothing too extreme. 1400 miles without a puncture as well.

If you're particularly after puncture free tyres for your commute there was a recent thread on them (try puncture and commuter in search box) and I think Specialized Armadillo's were also recommended.

I'll probably try Vredestein S-licks when I get a second set of wheels built - 1.4" (I think) and up to 90 psi.

Richard