• The page is "historically significant"

• The page has special meaning for me, personally

• All of the above.

Almost all my Kirby pages, for instance, fall into the latter category, since they are mostly early Silver Age.

One of my Kubert pages is from the first BRAVE&BOLD Hawkman story, featuring Katar and Shiera in costume and descending to Earth for the first time. It's also from a comic that blew me away when I bought it new, off the rack.

I have a Dick Sprang piece, recreating the first page of the first Batman story I ever read. Some serious significance, there!

And, of course, from the first SUPERMAN vs THE AMAZING SPIDER-MAN, I own the double-page spread upon which the characters actually meet for the first time.