I dropped into the Phoenix Art Museum on a whim this past Tuesday night (Tuesdays are the night it's opened until 9pm which is also FREE ADMISSION night). I was pleasantly surprised by their collection and their special exhibits. It's not at the same level of most large metropolitan art museums, but it has a lot to see and there are a few items that stand out. The building is somewhat maze like, but that makes it fun and interesting, as well, as the chance to return to see things you missed during previous visits.
Remember, Tuesday nights are FREE, so it's a great opportunity to take the family away from the TV and see something different.