From my perspective, United Airlines had two things going for it: membership in Star Alliance, and that lovely arrangement of Rhapsody in Blue that they play as you board. Things got better when they aligned themselves with US Airways (America West, re-branded). I had received consistently good service from America West, and that seems to have carried over through the various mergers and bankruptcies. Plus, it’s nice to be able to add a long connection in Vegas, so you can play a few hands on the way out of California.