I Boulder, go to Exotic Aquatics. They are pretty good for fish. They might be a few dollars higher than some, but I have gotten quality stuff there and you cannot drive outside of town for the difference in price, if there is any at all. I don't buy coral there anymore since I am mostly into SPS and I don't buy SPS under LED, but they have some nice stuff from time to time.
If I do go outside of town for fish, I go to Aquamart (which is a haul) or Great White up in Fort Collins (they have cheap clowns when I was in there last weekend).
There are other stores around, but they don't meet my quality standards, but perhaps I am too picky of a ******r anymore.