I like Primos. They're light, fast, and pretty inexpensive - $16-20 apiece. I run them down to the cords and throw them away, and never have to worry about premature failures. The rear tires usually last 3500-4000 miles for me. The fronts, longer. The last flat I had with a Primo was about 4 or 5 years ago, when I ran over a sharp stick in the rain. That put a nasty-looking cut right in the middle of the tread, but I patched the tube and ran that tire right down to the cords, just like all the others. However, I generally stay off shoulders and ride around patches of junk I see in the road. There's no point in tempting fate!