Delta Green RPG
There is a pretty amazing Humble Bundle on the Delta Green RPG. A ton of content (58 items including VTT support) for $25.
This may be of interest to any Call of Cthulhu (CoC) fans. Delta Green was originally released as a supplement to CoC before becoming its own game, so the rules/mechanisms (percentile system) are the same as CoC (7e).
Description:
"Born of the U.S. government’s 1928 raid on the degenerate coastal town of Innsmouth, Massachusetts, the covert agency known as Delta Green opposes the forces of darkness with honor but without glory. Delta Green agents fight to save humanity from unnatural horrors—often at a shattering personal cost.
In Delta Green: The Role-Playing Game, the players are those agents. They fight to keep terrors from beyond space and time from infecting the world and claiming human lives and sanity. The Handler is the game moderator who creates and interprets their world, presents the unnatural horror that they investigate, and describes the awful aftermath of their sacrifices."