Here's a partial list of pulp RPGs, supplements, and resources.
3 2 1 Action.
Acthtung! Cthulhu.
Adventure!
Amazing Adventures.
Atomic Robo RPG.
Broken Compass.
Daredevils.
Daring Tales of Adventure.
Daring Tales of the Space Lanes.
Dicey Tales.
Dime Heroes.
Everyday Heroes.
Fate Accelerated.
Fate Condensed.
Fate Core.
Forbidden Kingdoms.
Gear Krieg.
GURPS.
Hollow Earth Expedition.
Indiana Jones.
John Carter of Mars.
Justice Inc.
Lucha Libre Hero.
Mercenaires, Spies, and Private Eyes.
Modern Dispatch 42, 46, 86, 98, and 110.
Outgunned Adventure.
Pulp Cthulhu.
Pulp Hero.
Pulp Heroes d20 (from Polyhedron 149, Jan 2002).
Rocket Ship Empires 1936.
Rolemaster Pulp Adventures.
Savage Worlds.
Space 1889.
Spirit of the Century.
Strange Tales of the Century.
Thrilling Adventures.
Thrilling Tales.
Tomorrow City.
Torg.
Troubleshooters.
Two-Fisted Tales.
World War Cthulhu.
Young Centurions.
Two special mentions.
Pulp Hero. The single best general introduction to pulp adventure gaming I've ever found.
Jess Nevin's website. Link. Jess is a librarian with a deep love for pulps, the fantastic, and Victoriana.