Back when I started this blog, it was partially to throw my hat into the OSR. Of course, now WotC has their PDFs for sale again and I've mostly moved on from DnD Next to 13th Age, but I still try to keep my eye on the OSR.
Fantastic Heroes and Witchery is a pretty sweet new Retro-Clone that treads some new ground and focuses as much on Weird Sword and Sorcery as DnD-style fantasy.
And it's free.
I can't recommend it enough.
Check it out here.