Umpteenthing Lois McMaster Bujold's
Vorkosigan Saga as one of the best sf series ever, much less best DRM-free ebook-available.
Also at Webscriptions, Mike Resnick's excellent
Kirinyaga collection of award-winning short stories set in that milieu. Sadly, the
Santiago and other series I wanted from him that used to be available MultiFormat via Fictionwise have disappeared, and resurfaced via a new e-publisher who seems to DRM them.
Away from Baen and Smashwords, Peter Watts'
Rifters trilogy, published by Tor, which he offers as a
free Creative Commons download on his website, along with practically everything else he's written (and a tipjar) is pretty darn good, if a bit bleakly depressing.
Lawrence Watt-Evans'
Ethshar fantasies are well-written and enjoyable. All but two books in it are available as DRM-free MultiFormat via Fictionwise, and he's been writing the
newer ones as online serials supported by contributing fans who get a bonus copy once the latest book is officially published.
I'll admit I haven't got around to reading Mayer Alan Brenner yet, but I thought I'd give him a mention because he's been putting his out-of-print novels from
The Dance of the Gods series as
free Creative Commons downloads online, in the hopes of getting enough buzz to have them reprinted in paper. He seems a pretty cool guy who understands the potential of e-books and various copyright issues, so I wish him luck with his efforts.
Similarly, Baen author John Dalmas is putting his
OOP backlist online.
Via
e-Reads, there's plenty of DRM-free MultiFormat sf/fantasy available for sale on Fictionwise and Webscriptions, with some really good stuff by authors like R.A. MacAvoy (award-winning fantasies, recommend
Damiano trilogy and
Tea with the Black Dragon), Greg Bear (award-winning sci-fi, recommend
Blood Music), Fritz Lieber (
Fahfrd and the Gray Mouser), Harlan Ellison, Susan Shwartz, Dave Duncan, et al. I've picked up a lot of them during Fictionwise's recent 50% off coupon offerings and the ones I've read have been well worth it.
Other DRM-free sf/fantasy publishers on Fictionwise include Wildside Press (classic reprints and original stuff by established authors like Brian Stableford), Wonder Audiobooks LLC (golden age/60s-70s sf by Ray Bradbury, Judith Merrill, Fredric Brown), Mundania Press (midlist light fantasy reprints of authors like Don Callander, Anne Logston, Piers Anthony). Plus there's authors who offer their stuff to Fictionwise directly (mostly short stories).