I've had very good luck with the following:
* Vittoria Randonneurs and Randonneur Cross
* Bontrager RaceLite Hard Case
* Specialized Armadillos
* Specialized All-Condition Sports
I've yet to flat the Randonneurs (which means it'll happen today). They are not, however, very spry.
The Bontragers are nice tires, too, and I've only flatted those once the rubber was really, really worn down. Same goes for the Armadillos.
The All-Conditions are definitely lighter, but I'm not sure how they hold up. They're my "training" tires, so I'm not as careless with them (meaning I actually avoid glass and whatnot), but I've done a fair amount of dirt riding with them with no issues.
Both the Randos and the All-Conditions have a reflective sidewall, which is nice.