Aquarium Oddballs is a great little store and online retailer run by a friend of mine, Scott. Their quality products and amazing customer service brings me back everytime. If you need something he doesn't have, he'll do everything he can to get it, and will usually give you the best price.
Aquarium poetry is the blog of aquarist Dusko Bojic. Dusko's blog features a number of informative and top quality articles, photos, and journals of his own tanks.
Fish4Life is a blog by a fellow aquarist who goes by the screen name, LR. The site is full of great articles on various topics in the aquatic hobby.