So far Panaracer Pasela TGs are my favorite. Not one flat except from a goat head(which will puncture anything) and I know I have ridden through glass and a lot of other crap. They roll nicely, aren't that heavy, look good, and dont cost a ton. I'm not such a fan of Gatorskins because I got a flat on the very first ride.

Gp400s are the best I have tried. Great tires in every way but they cost a lot.