You know, thinking about it, I think my all-time favorite moment in any interactive entertainment product might just be finally beating this cheating son of a bitch in Super Street Fighter II Turbo as a 12-year old.
God, I spent my childhood on that guy. The fact that my 16-year older brother (who had played the game even more than me) couldn't pull it off made it even the more sweeter. 
Either that, or one of the countless nights I stood up with my cousin playing Marvel vs. Capcom 2 until the sunrise.







