Programs (and yearbooks/media guides) are the part of my collection that I enjoy the most. I collect mostly Orioles, Baltimore Colts, and NY Rangers items in addition to ephemera related to games that interest me.
A few years ago I tracked down a program from the first game I attended with my Dad, a 1960 doubleheader at Yankee Stadium versus the White Sox.
This one is from a 1951 exhibition game between the Brooklyn Dodgers and the International League Orioles. The Dodgers barnstormed their way north from spring training. The O's were a Phillies farm club in 1951.
Dodger lineup for the game:
Don Thompson CF
Carl Furillo LF
Duke Snyder RF
Jackie Robinson 2B
Gil Hodges 1B
Roy Campanella C (the scorer listed him as 'Campy', I love that)
Pee Wee Reese 3B
Rocky Bridges SS
Preacher Roe P
What a kick it must have been for the locals to see those Dodgers stars in person.
Here's a pretty beat-up 1953 IL Orioles program, their last year as a AAA club (if you don't count some of those 1990s Orioles teams!
Lastly my oldest hockey program, from a Rangers game in 1943. I picked it up because of the cover art.
The awesome US Armed Forces content was a nice bonus.