I'm finding oil in the spark plug well, where the coil attaches. It's on cylinder 1,4 and 5.. And there's a head bolt in each of those places. The oil was worse in cylinder 4.
So it's either leaking through valve cover gasket..
Or is oil under enough pressure to actually seep through the spark plug threads, and or head studs?

my friend had this same problem in his subaru... i'll ask him what it ended up being and get back to you!

so in my friend's case, it was indeed the valve cover gaskets. he said that inside the valve covers, there are spark plug gaskets too and those were all warped and crappy. this is where i would start