I hate flats a little less than cockroaches or ants so I sacrifice a little performance for puncture resistance.
These are my current tires and are superb
http://www.specialized.com/us/en/bc/...jsp?spid=42100
About 1k on them without any problems, and they hold their psi the longest of any tire I've ever used.
I have these on my Langster and they have about 5k on them still look new. Only 1 flat and it was a piece of wire that would have put down a car tire. They do drop psi a little so check em' regularly. That, and they're really hard to find outside of ebay.
http://www.maxxis.com/Bicycle/Traini...s/Re-fuse.aspx
I rode continental gp4000's last summer and they were great performance tires but I got limited miles out of them (1200 or so) and 3 flats, the last flat was after they self-destructed with splittting.