|1951 Topps Connie Mack All-Stars, Connie Mack|
Connie Mack All-Stars featured retired greats and a die-cut around player silhouettes, so you can fold the backs over and stand them up.
|1951 Topps Major League All-Stars, Yogi Berra|
Major League All-Stars used active players on the same die-cut design and prove almost impossible to find today, possibly due to legal wrangling with Bowman over contract exclusivity.
|1951 Topps Team Cards, Chicago White Sox|
Team Cards are full-squad photos. Topps printed only 9 of 16 active teams, possibly for lack of pictures at design time.
It's quite expensive to build any of these three sets, given their rarity. Find a wealth of detail on their checklists and printing peccadilloes in The Candy Men post at Topps Archives.
The Topps 60th baseball anniversary came to mind when I came across a 1980s set summary at the This Card Is Cool blog, another great source of card scans and writing from any era. Author Ryan G turns out more than 1 post per day, so you'll never run short of reading material. Combine our decade profile posts and you've got all six covered!