question to sketch card collectors

[drestudios]

Here's a question to all you hard core sketch card collectors. Which Marvel characters are most sought after? Reason I ask is that I'm working on a set for UD as we speak and I'm finding myself speding too much time trying to figure out who to paint (not for APs, general set).

So instead of raking my brain, I figure I'll ask the community and try and meet demand.