Tell me how to spend my money

My lovely and wonderful wife got a gift certificate to for Christmas, and I have a bit of a problem -- I'm not sure what to spend it on. Two thirds of it I am generously donating to you, good blog reader. Sort of. I'm getting the complete run of the 1985 "Who's Who in the DC Universe" and subsequent updates so I can hunt down more ridiculous and mock-worthy characters for your belittlement and enjoyment.

But that leaves me with about thirty bucks to spend, and I can't figure out what I ought to do with it. I don't want to just get the current issues I get from my regular store, but I already have most of the "big" sets I'd want.

So I thought I'd ask you all -- if you were recommending a "must have" graphic novel or trade paperback to someone who loves comics, what would you recommend? Here are a few sets I have and love, if that helps:

(Edited to add: Those are ones I already own, not ones I am thinking of buying. Just to give you an idea of the kind of thing I like.)

Lay it on me, intelligentsia! Tell me what I need to buy with my remaining monies. Otherwise I might just say "Screw the blog readers and their 'Who's Who', I'm dumping all that and instead getting the 'Complete Calvin and Hobbes'"!