I was very impressed with Continental's Business First when I used it earlier in the year, so would add my vote to them. Non-stop, very good food & service and it's only a 6hr or so flight (whereas you're looking at 10hrs plus if you connect).

What's more, on the way back home as I understand it you'll clear INS formalities at Dublin so arrive as a domestic flight. Whilst less of a problem for US citizens, it's still going to save you some hassle...