Super Mario 64 is the first game to come to mind. I'd never owned or played a console until that Christmas when my parents dropped it and Diddy Kong Racing into my and my brother's laps. Seriously, I don't think I could've found a better introduction than I did. Pokemon: Yellow Version, Paper Mario, Donkey Kong 64. OoT, all had a similar effect. Later on Guild Wars, Kingdom Hearts, Chrono Trigger DS, The World Ends with You, and Super Mario Sunshine (yes yes, I know it's not as good as the rest), all took me away just as completely.

Zelda games. specially the N64 iterations. the music is just awesome. i would buy the game just for it.

Mario Galaxy, LOZ:WW, LOZ:LTTP, Cave Story. The most recent "magical" game I've played is Mark of the Ninja. It's incredible. T_T Can't wait to play more.