I think the day flights from New York or Boston to London on BA and AA are vastly better than evening flights for diminishing the effects of jet lag (I do about 10 trips a year). I prefer BA to AA, although sometimes the price on AA is considerably lower. However, it looks as if the earlier poster has given you a great link for BA. Incidentally, if you are taking the day flight, BA's World Traveller Plus is actually pretty good -- lesser food, smaller seats, but enough leg room for me (at just bout 6'2"). The price can be very good. I'd be a lot less enthusiastic abotu WTP if you were taking the evening flight.