Here’s an interesting project to make a version of Catan that’s accessible to younger children.
Doomed is a card game designed to recreate a certain video game. Like All WarpSpawn games, this is very much a do-it-yourself project.
Hitchhiker’s Quest For The Galaxy is a home-brew card game based on the book of the same name.
You gotta love a game which specifies that “the most depressed player goes first.”
Shaun of the Dead is free card game based on the very funny movie of the same name.
Reanimation is very highly rated at Board Game Geek. And it is free.