I had Conti Ultra Gatorskins on my commuter (700 x 25s).
I liked them for a while, but started getting flats routinely.
Don't know if they wear out quickly or what (I have maybe 800 miles on them). Usually I like to rotate them every so often (front to back) since they are not front/rear specific. Don't know if it does any good but it generally makes me feel better!
That said, I just swapped them out for Bontrager Race Lite Hardcases. I believe they are re-badged Vittorias, but I'm not sure. Any Trek dealer should have them. They claim a "triple puncture protection" and so far, they have held up (only about 100 miles on them thus far).
The Bonti's, I have to admit, seem to roll very nicely to me. Very plush feel to them, yet they take the abuse my commute dishes out.