Poison Girl is kind of a dive -- pretty weird, but worth checking out if you are looking for strange places. There's an overgrown back patio area with a giant Cabbage Patch Kid and an enormous model of the Kool-Aid man. The place is also known for having a wall full of pinball machines. Check it out if you want to see somewhere very "Houston strange." Also, house mixed drinks are dirt cheap.
Photo via Poison Girl Facebook page