Let's get this going.
What's your favorite OSR?
Ones I have, * means played.
OD&D *
AD&D *
Basic Fantasy *
Castles & Crusaders
Old School Essentials (OSE)
Hyperboria
OSRIC
Advanced Labyrinth Lord
Swords & Wizardry *
Pathfinder 2e
Dungeon Crawl Classic
Tunnels & Trolls
My go to is AD&D...
Warlock is a rules-light version of warhammer fantasy roleplay. The core dice mechanic is d20+skill. Combat rolls are opposed rolls, sword vs mace skills for example. It uses the career system from wfrp so characters start as something like rat catcher and change careers to advance. If you like the warhammer old world but don't want a crunchy game, I'd recommend it.