Well, if we get into past tense, I once had a killer comic book collection. About 1500 DCs, ranging from 1936 to 1961. Superman ranging from 7 up, complete from 83 thru 149, complete runs of Congo Bill, New Adventures of Charlie Chan, near complete runs of Gangbusters, Mystery in Space, the early silver age Atoms, Green Lanterns, Flashs, etc. (never did score a Showcase 4 or 8, though...), shit..I could go on for a while.
And no, I do NOT want to see a current Overstreet Price Guide, thank you very much.