Fictionwise is my favorite ebook store on the web, though they were recently bought by Barnes and Noble so we'll have to see if they remain my favorite. You can buy plenty of great books in ebook form here, usually saving yourself a lot of money and the lives of quite a few poor trees as well.
The only thing wrong with Fictionwise, so far as I can tell, is that they do not yet offer the wonderful stories by that wonderful adventurer story-teller, which is to say Eaglethorpe Buxton, which is to say me. But maybe soon. Also, they could use more epub, and I don't even know what that is, but it does put me in mind of a pub I used to visit called the Upset Elf Pub, which as you can see, has a pub and an e in it. The Upset Elf had some of the finest ales and chubbiest serving wenches I have ever, um... experienced.
Here's to good times!