Originally Posted by PaulRivers

First, the first thing to do is track down where the flats are happening. If they're happening on the inside of the wheel (the rim side) you need new rim tape and a better tire isn't going to help. I've also had several flats right at the stem, and a better tire wouldn't help that either.

I personally have never had a flat on the outside of the tire since I started riding on Panaracer TServ Messenger tires, like these:
http://www.lickbike.com/productpage....=%271766-28%27

That was the first link I found - they come in practically every size possible, and mine came with a reflective strip on the tire.

Last week I was riding with a guy who had the Vittoria Randonneurs and he said he hasn't flatted on those, either. I think they're a little cheaper.

If you want really puncture resistant tire, though expect a harsher ride because of it, the two tires that get very good reviews are the Specialized Armadillo's and the Schwalbe Marathon tires. But like I said, ride quality suffers on those (haven't noticed a difference on the other tires).