LAS is the worst I've ever had to deal with.

PHX used to be horrible, with far too few buses running to/from the AA/WN terminal. I learned to just use the train to get to the "everybody else" terminal and then ride to/from there. But now the train goes all the way to the rental cars, and it's a pretty good setup. That said, the rental car facility is so far away, I feel like there should be a bar car and ability to earn Amtrak points.