I'm a steel frame/carbon fork fan, as this is more comfy to my 51-year-old body than others. It's all a personal choice, as I agree with others that you need to ride a few different types and get a frame that fits.
I bought a Serotta after my brother let me ride his steel frame/carbon fork Serotta with Ultegra components. His has a custom frame ($$$$) and mine was the closest stock frame that fit me. I bought mine on eBay for $650 when it was 3 years old. His was something like $3k+ around 6+ years ago. Regardless, they do a nice job and the quality is hard to beat. Here's their site:
2009 SEROTTA
Another choice in that is not as well known is Kirk. David Kirk used to work for Ben Serotta, but went out on his own a few years back. He's also a Lotus nut, having owned a MkI Lotus Cortina that I once stored in my basement for the guy who sold it to him. He later sold the Cortina and bought a Birkin Seven. Turns out that he designed my Serotta Atlanta frame, which was one of the last ones that company did with a lugged frame. Check out his site, as he appears to be VERY meticulous and will build a custom frame to fit your specific needs:
http://http://www.kirkframeworks.com/index.htm