I'm slowly coming around to Cookie Monster Opeth - it's gone from "turn off" to "laugh at" to "hang on there's some pretty good music under there", which I'm still moving in the right direction from. Also I've got an new Opeth T-shirt in pink which is nice.
Otherwise Magma, Tool and assorted scandanavian prog and jazz are sitting happily at the "difficult" end of the spectrum at the moment (varying the definition of "heavy" a bit). Also, speaking of which, Panzerballett: