These are ebooks that I have read recently and that I enjoyed. I have arranged the title so that the most recent ebook is first.
The Riddle of the Frozen Flame by Mary E. Hanshew
Mediocre (at best), turn of the century murder mystery. I finished it, but no great shakes.
Scarhaven Keep by J. S. Fletcher
Murder mystery published in 1922 but set in 1912 (perhaps wrtten then too). Nice murder mystery with amateur detective assisted by a large cast. British. Small bit of reserved romance thrown in.
Transit to Scorpio [Dray Prescot Series #1] eBook by Alan Burt Akers
A great "sword and planet" science fantasy along the same lines are the Edgar Rice Burroughs 'Mars' books.
The Middle of Things by J. S. Fletcher
A mystery classic ebook from 1922 and free because it is in the public domain. A good read with plenty of plot twists.
Murder Crops Up eBook by Lora Roberts
5th Liz Sullivan mystery. I have read the previous ebooks in this series and they are both original and have some very good characters. I have enjoyed them all.
The Strange Adventures of Rangergirl eBook by Tim Pratt
Science Fiction or modern fantasy this is a fun story about a comic book artist who finds a secret door into another world and after she opens it her comic book world starts coming to life.
Murder at the Worldcon: A Science Fictional Roman a Clef by J. D. Crayne
Not really a science fiction book at all, but definitely a murder mystery. Takes place at a SF convention and fans will enjoy it as much as mystery buffs. Crayne writes a good mystery.