I have a bunch of alternative comics creators', but those are really just inscriptions with little drawings. Some very great ones included in these, Paul Hornschemeir, Alex Robinson, Liz Prince, Jessical Abel, Bryan Lee O'Malley, Zach Sally (from Low), R. Kikuo Johnson... and some I've forgotten.
Alfred Molina on a Fiddler on the Roof playbill.
Some Red Sox players.
My favorites are probably Michael Showalter on the Stella shorts DVD, Eugene Mirman on his latest CD, and those two, Leo Allen, and Zak Orth on their tour poster.