I second the recomendation for Panaracer Pasela TG. Rode from San Francisco to L.A., and never got a f!at.
AJS said:~ Panaracer Pasela Tour Guard's. Pretty light, pretty cheap, tough, and wear good.
~ Vredestein Fortezza's. Same as above, but with a slightly better ride. Used those and Vitt Corsa's on my roadie. My current Vred Campo's are exactly the same as a Fortezza, but wider with low-profile knobs. I've beat the crap out of them without a glitch yet.