To list of a good handful of my favorite childhood video games:
Sonic The Hedgehog
Super Smash Bros.
Mr. Pac-Man/Mrs. Pac-Man
Legend of Zelda
King of the Fighters
Marvel vs. Capcom
All basically old-school series from classic game consoles such as Sega Genesis, N64, SNES, Gameboy/Game Boy Color, Sega Dreamcast, PS1 etc.
And I still play all of these series now(mostly the newer games in the series for the newer consoles such as PS3, Xbox 360, Wii etc.), so they're a part of my childhood and also a part of my present life.
You can never outgrow the classics.