My favorite publisher is Baen. Now I come for the content, I love their sci fi -- but I particularly like their DRM free policy and their reasonable prices. Heck, you can try out over 100 of the books for free via their Baen Free Library.
www.baen.com
I just became aware of BeWrite books:
http://www.bewrite.net/ I think one of their editors participates here. Again, reasonable prices, DRM Free. Seem to have a variety of genre's. Am looking now to see which book to try.
Lee