b&h photo

My favorite online camera store is B&H Photo, perhaps the world's largest purveyor of cameras, film, flashes, and everything else photo or video related. I've always been able to find anything I've needed for my photo needs, from flash diffusers to all the different types of slide film you could ever want. Not only do they have an incredible selection of items, but they ship quickly and their prices are actually really competitive. (And if you're not in NY State, you don't have to pay sales tax!)

The thing about B&H photo is that it's run by a group of ultra-orthodox jews in Brooklyn. This leads to some interesting business practices; for example, the store is closed on every Saturday (since it's the Sabbath) and on the entire week of Passover--their website even shuts down then.

Nonetheless, the store has gotten rave reviews, and I've purchased over several thousand dollars of equipment from them (often at prices much less than I've found anywhere else).