2.2l Ecotec

I've got a pretty bad oil leak that I can't locate. It appears to be coming from behind the oil filter cap. I've verified that the oil filter cap is not leaking, and I've verified that the valve cover isn't leaking. What else is in this general area? Too many hoses in the way to get a good look and I won't have time to properly take it apart until this weekend. Any thoughts?

Head gasket oil leaks can be hard to pinpoint (especially if the engine is dirty & oily).