I like those Masterwork Maps books. I always thumb through them during my browsing visits to my FLGS. One day, when I have some extra cash and it's my turn to DM again, I'm going to pick up a couple of them.
I don't mind pretty maps, as long as they're functional. Some of them look like they've been created just to show off the software the company purchased though. Especially those 3/4 isometric maps. I can't stand those. They look nice, and 3D is cool, but I don't like walls on maps obscuring floor details.
JediSoth