Castle Panic is pretty fun for a kids cooperative game.
All of you are defending the castle from an onslaught of baddies coming in from the forest. Everyone gets cards each round to spend/trade that can damage/kill/repair with various restrictions. As with a lot of cooperative games, it starts easyish, and then things get harder.
And for a non-cooperative game, Munchkin. It's all fun and games till someone tries to win, and then everyone gangs up on them. The monsters are really silly, some of them are internet jokes, e.g. the one of the monsters is a Dread Gazebo.
All of you are defending the castle from an onslaught of baddies coming in from the forest. Everyone gets cards each round to spend/trade that can damage/kill/repair with various restrictions. As with a lot of cooperative games, it starts easyish, and then things get harder.