PRINCE OF DARKNESS for me. So much so that I preordered it through Shout, paying roughly $29, to get that awesome poster. MONSTER CLUB is a close second. As for there not being a lot of new-to-DVD titles, I'm confident many of those will surface sooner or later. When they do, it'll just be that much sweeter when combined with all the great upgrades.
Arrow has some interesting stuff coming out as well, for those of us with region-free players. SQUIRM comes to mind.