I'll go strictly with sigs I collected:
I once met a Rutle and had the memento made into a custom 'exhibit' card:
Heeeeerrrrre's Johnny [Carson, for you youths]: met him at an Academy Awards rehearsal:
Ditto these:
Ray Bolger [Scarecrow in The Wizard of Oz]:
Gene Hackman:
Ricardo Montalban:
Cheech and Chong:
I got this one of Bill Scott [the voice of Bullwinkle and many other cartoon characters] at an ASIFA event in Los Angeles:
And finally,
schwinngg!