the new scott cr-1 is light and strong and in the USA now. Giant makes the one of the best value full carbon frames. The Orbea Orca is great as well as is the Kuota Khan (bike of the year in europe 2003) and the Kuota Kredo (light and stiff). Look has been making great frames, all be it not the lightest or cheapest, but great handling.
Lance swears by the trek's as well!
The specialised Roubaix Pro is a great frame. had good reviews. I like the tarmac better.
I guess it depends on your style of riding and how deep your pockets are.
The Khan and the look 486 are the least race geometry of the bunch up top and would be the best century long haul bikes. They also offers the most sizes. (a lot of carbon compacts are limited sizes)
The Scott is the lightest, and I think the orca is one of the most agressive geometries.
for some feedback on some of the frames