Add in another vote for regular GreenGuard Marathons (HS-420). Between these and Continental RideTours I have accumulated thousands of commuter miles without any punctures. Three years ago I bought a set of each for two different bikes as a comparison test. They're both holding up well. I used to get regular punctures from living next to a scrap yard. With these tires I still get sharp objects stuck in the tread. But so far none of them have worked their way through to the inside.
The Continental is cheaper and has slightly better traction in loose gravel, but they're pretty similar tires overall.