I'm sure you'll get lots of suggestions, but --

What kind of riding do you do today? What would you like to do?

Just to start the conversation -- lots of folks on this board ride carbon, lots ride Ti. I personally own a Titanium bike because I wanted a custom frame. To my knowledge, there are lots more folks who can build you a Ti bike a reasonable price than a carbon bike...so if you're thinking about a custom fit that is one consideration. As for custom builders, I liked my builder, Bill Davidson at www.davidsonbicycles.com. if I wanted another Titanium frame I'd go to him without reservation.

Gallery of a nice Davidson (not mine):
http://www.flickr.com/photos/huggeri...7603720434389/





As for larger scale builders, you should also check out Moots and Seven.