This thread is for pointing out free and bargain Science Fiction and Fantasy titles to each other. Please don't post any self-published books (unless you have read them yourself, think they are excellent, and you're not connected to the author in any way) and please do a search before posting to avoid duplicates.
Because Kindle freebies are the easiest to find, the majority of books listed here will probably be from Amazon. That being said, deals from other retailers and/or in other formats are certainly more than welcome!
In the event that no retailer is specifically mentioned in a post, it is safe to assume the deal is for Amazon US.
As always -- if a deal could span multiple subjects, please cross-post to ALL applicable deals megathreads.
This is pretty much the one time when double-posting is not only allowed, but encouraged. Seize the opportunity!
Keep in mind, most freebies last only for a day or two, so grab them fast!