I'm nowhere near the survival horror aficionado that Mr. Riley is, but Silent Hill 2 is amazing. Plus it's a pretty compelling two-person experience. But if you found Eternal Darkness boring, you might not have the patience for it, plus it's more along the lines of a horror drama instead of a slasher.

Obscure is fun if you're looking for some survival horror co-op. It's cheesy and flawed, but a great two player experience. You can read more about it here.