Good growing list so far. I'll add a few:
Return of the Living Dead
Night of the Creeps
Bad Taste - Peter Jackson film.
Dead Alive - see above, similarly absurd gore, which is part of the comedy
Cemetery Man (Dellamorte Dellamore)
Creepshow 1, 2, & 3
I would also suggest you check out the many earlier great horror-comedies like Abbot and Costello Meet......(Frankenstein, Wolfman, etc.), The Raven, The Ghost and Mr.Chicken, etc. There are many anthology horrors shows that often combine the genres like Tales from the Crypt and Tales from the Darkside.