What U.S. city consistantly has the cheapest flights to Bangkok?

Definitely Los Angeles and San Francisco, almost all the Asian airlines as well as the American carriers who fly to Asia and Bangkok fly out of those two airports. China Airlines (Taiwan) usually has the best prices although airlines like Cathay Pacific, Thai Airways (LAX) and Singapore Airlines often have specials to Bangkok. United often has pretty good prices as does Northwest, but the Asian airlines offer better service and in-flight amenities. I've been checking prices recently and air fares are really up there for the summer travel season, check around and you should be able to find a decent price somewhere. Good luck.