US airways used to be good for America, but they seem to have let their A330-300's go a little bit. I suppose when they upgrade them, they could be good again.
I personally like VS for the USA (LHR only), as the meals are good, a couple of drink rounds, V-port and for New York, good timings on flights.
MAN-MCO on VS should be good from april, brand new A333, with very very up to date IFE!
Going east, I keep hearing good things about Etihad, and for India, jet airways.
I suppose it all depends on what you like on a flight though. Do you just want to get from A-B with minimal effort, or to be left alone, or to be entertained and fed all the way?