I have also been using Gatorskins. They're ok although I think that they seem to get more road debris stuck in the tread. Might just be because the roads here in the city have a bit more debris. I just took delivery of 2 Michelin Pro4 Service Course 700x23 tires. They seem to have good reviews online. They are on sale at performancebike.com for $40 now.

http://www.performancebike.com/webap...&storeId=10052

So will see how they fare. I don't expect them to be any more flat resistant than the Gatorskins. I guess they should be able to give better ride quality. I doubt that I'll escape stuff getting stuck into the tire. So I fully expect that I will need to check the tread for objects almost daily (like I do now).