One of my bikes came with Bontrager Race Lite Hardcases on it. Boston streets shredded 'em after about 1000 miles. I now run, and am extremely happy with, Conti Ultra Gatorskins. For me and my commute, they are the best balance between flat protection and speed. I gather from the many threads on this topic that the Armadillos and Marathons offer better flat protection, but roll slower.