I've got some Vittoria Zaffiro 25's. They have a decent amount of tread for the road and seem to be handling the constuction area gravel on the Trinity Trail without trouble.
I did buy some of the Performance house brand Strada-K's last year. Blew a tire out with somewhere between 700 and 800 miles on them. Won't be buying those again, though that's probably a reasonable lifespan for those tires.
Blowout by
Yo Spiff, on Flickr