The Gold Standard from the Dragonsfoot forums.
Labyrinths of Madness by Gavin Norman of City of Iron.
Dungeons & Dragons Variant Edition, by Don Jolly. Be sure to check out his little games Gax & Vox, too! And his book, The Flapjack Canyon, free in PDF from Lulu.com.
Options for Swords &Wizardry Complete: Psionics, by Cameron DuBeers. Also, be sure to check out his module There's Something Rotten in Riverton, which I can't get to print in booklet form.
The Cave of Nanoc, by Dylan Hartwell.
Blood Ceremony of the Voivode, by Ben Djarum.