Superman

Alex has issues. (Get it?)

For every collector there is that “Holy Grail” item that a collection could not be complete without.  If you’re a philatelist (stamp collector) it may be the British Guiana One-Cent Black on Magenta stamp, or if you prefer coins you might be in the hunt for an 1849 Double Eagle (Google these to see how much they’ve sold for).  If, however, you happen to be a comic fan there’s usually two different comics at the top of your list.  One of them is either going to be Action Comics #1 or Detective Comics #27, the first appearances of Superman and Batman respectively, for obvious reasons.