X-link to the DRM-free thread for two rather nice sfnal bundles:
Humble Bundle Fantastic Fiction presented by Subterranean Press features a good spread of the noted specialty publisher's reprints/new novellas from well-known authors such as Hugo/Nebula/etc. winners Connie Willis (an excellent and recommended almost-complete short stories collection), John Scalzi (his latest
novella short story collection from them, IIRC), Cherie Priest (another in her Hugo-nominated Clockwork Century series), Joe R. Landsdale, Harlan Ellison, Alistair Reynolds, and more. ETA: For horror readers, there are also two offerings from Clive Barker and Robert McCammon, which apparently continue stories in their popular settings.
The Steampunk Bundle from StoryBundle, curated by World Fantasy Award-nominated editor Cat Rambo, contains a mix of backlist and indies, and while not as obviously an auto-buy as the HB, is IMHO also fairly good value for money if you like steampunk, and I'm certainly willing to give it a try at the top-tier for the value-add of some interesting-looking small press anthologies.