I wouldn't group United/Delta/American together. From my experiences and those of most travelers I talk to, Delta is certainly a step above the other two, and A

I wouldn't group United/Delta/American together. From my experiences and those of most travelers I talk to, Delta is certainly a step above the other two, and American is probably second. United completely mishandled the Continental merger, and has had a host of reliability and service issues. My main gripe with Delta is their continually devaluing (without warning) miles program. Alaska, meanwhile, has one of the most widely useable miles with their many airline partners for earning and redeeming.