If you're in coach, fly on AA. Two reasons:
1) in-seat power
2) more comfortable seat.

AA 777s are some of the only planes in the sky with power in coach. On long haul flights, who cares about the entertainment system when you can watch your own DVDs on your own laptop?

I've flown JAL coach to NRT, from JFK. It sucks. I've fly AA to LHR on the 777, several times, and it really is, I think, the best coach in the skies (possible exception: Virgin).