The Legion of Doom captivated my imagination when I was 5; the
Superfriends were never the same without that big moving
Hall of Doom that looked a bit like
Darth Vader's head. For years afterward my playtime adventures were influenced by the 12 Superfriends and their 12 arch-enemies in the Legion of Doom.
Of course, I found out to my surprise that there never were 12 Superfriends and 12 Legion of Doom counterparts. That explains why I couldn't ever figure out which heroes went with which villains. But, here are the members of the Legion of Doom from the 1978 season:
Bizarro
Black Manta
Brainiac
Captain Cold
Cheetah
Giganta
Gorilla Grodd
Lex Luthor
Riddler
Scarecrow
Sinestro
Solomon Grundy
Toyman
I originally included Joker in the list, but I'm pretty sure he wasn't in that Legion of Doom. If I'm wrong, let me know...