I'm pondering this.  I switched from Schwalbe Blizzard Kevlar a few months ago, as I was averaging a puncture a ride with them.  
I went with Bontrager Hardcases, as Zack has.  Not had a puncture with them in a couple of thousand miles, so they have done their job.  But they are getting quite cut up and they are not that nice to ride - they feel a bit solid.  So I'm thinking of trying something a bit softer for the summer, and for PBP.  
What should I go for?  I've got a set of nearly new Michelin Pro Race 3 in the garage (came with some wheels I bought), but they just seem too flimsy and I don't want to go back to fixing multiple punctures again!  But they get good reviews and I'm sure they would be better to ride, so I suppose I should try them out before PBP...