Since the beginning of the whole eBook trend I've refused to buy e-books from Amazon exactly because of their DRM, and recently I went looking around for an alternative and discovered Smashwords were I can buy the books and get them at least in ePub format (some also in other formats). They've been getting a steady stream of money from me ever since. (No, it's not a subscription, it's me being an avid book reader).
No idea of how good or not they are compared to other alternatives, but they seem to have more than enough choice for my needs and do satisfy my criteria, - the same as yours - which is that I when I download a book I get to keep it and read in any way I see fit.