Since romance and mystery have their own dedicated threads, here's sf/fantasy/horror/historical (I don't imagine we'll get enough of that last to make up its own thread).
NB: If someone has at least one thing free/on sale, I'm not going to bother to direct-link all of their special offers separately (unless it's the only thing in a 2-page listing), and just link to their author page instead to save time, especially since Smashwords doesn't auto-show if something's on sale when you do a keyword search or look at the listings in the profiles.
@ Smashwords
Stephen Ames Berry (
ISFDB entry) offers his 1984 Ace-published MilSF space opera for free:
The Biofab War
Elaine Corvidae (
ISFDB entry) who is published by Mundania Press offers all her Smashwords stuff for free, some to download, others using provided coupon.
Linkage to her author listing.
Lazette Gifford (
ISFDB entry) offers a number of short stories for free download or free-with-coupon, and her longer works are set to 50% off.
Linkage to her author page.
Sylvia Kelso (
ISFDB entry) has
her entire Smashwords catalogue on sale @ 50% off using the coupon code provided ($2.99 regularly). 3 epic fantasy novels published by Five Star & a collection of sfnal essays. Read some sample stories and essays over at
her Book View Cafe page.
Moyra Caldecott (
ISFDB entry) writes historical novels (some with fantasy element) set in assorted ancient times, some of which are at YA level.
Much of her catalogue is 25% off using coupon and it seems likely that other stuff from her re-publisher "Mushroom Publishing" will also be discounted, but frankly you can get these a lot cheaper
via Fictionwise using their discount coupons.
Kathleen Guler, whom I noticed last year, is either very small press or glorified self-pub (
ISFDB entry; her publisher imprint seems to only carry her books, as far as I can tell). But her books are or were distributed as far as two of my local library systems, and were interesting enough that I was thinking of getting the 1st volume in her 5th century British historical Arthurian-related fantasy-ish adventures when it was offered at a 75% discount to $1.99 (and in retrospect, probably should have, since the library turfed their copy some months later). This time around, she is only offering a 25% discount on her $7.99 books so I think I'll pass considering that and $6 is about what I'd pay for a Baen-backed author with a good reputation in the field and way too pricey for a probably self-pub unknown. But
here's her catalogue if you've read her before and want e-copies with a minor discount.