I'd love to watch a zombie apocalypse anime. HSotD is a parade of cartoon titties floppin' around, occasionally interrupted by zombies, and the story just isn't strong enough to make that not annoying. However, I'm still following it to see if it redeems itself, because it has real potential.
Reading the Hayate the Combat Butler manga and it's not bad. Does the anime also break the 4th wall?
Also, what are some great horror anime series with more emphasis on story than combat sequences?