Maybe I spend too much time with my fellow degenerates on OMNI but the first airport that came to mind when I saw this thread was CUN.

Which I think of as "coon."

As another poster said, anything pronounceable as a word on its own is so pronounced (BAG, PEK, SYD, MEL), except for LAX and BOS, which will always be "Logan" to me. I refer to a few others by other names: BKK is simply Bangkok, CDG is Charles de Gaule (don't ask me why, I have no idea), LHR is Heathrow, and NRT is Narita.