Favorites:

PDX - good shopping (heck, I've paid the $3 for the parking garage to go shopping there...oh, did I just admit that? LOL...and MAX isn't really a feasible option for me, since I live north of the Columbia), really good beer and...well...it's home. LOL

SEA - just an all-around, well-planned out airport. Except for the QX mess at C2.

EWR - even though it's busy, when I transited through there, it didn't seem insanely busy in the CO terminals (whereas JFK and the DL terminals...I felt claustrophobic).

Least favorite:

GEG - If you're on AS/QX or Frontier, it's a heckuva long walk to the rental car counters. Plus, it's a really, really, REALLY boring airport (like, there-isn't-enough-alcohol-in-the-world-to-get-me-through-the-boredom boring). I don't know about the A and B concourses, but the C Concourse is extremely, extremely boring.