I have a Lemond Buenos Aires and I find it very comfortable. It's a steel spine with carbon cockpit. I swapped the saddle for a selle italia flite, and I'm good to go. I also have my bars a bit higher than most and that helps. The biggest thing is get one that fits you properly. You can always change a few things later.

BTW, I've also heard good things about the Roubaix mentioned earlier.