To be honest I do that even today but it's a very tough choice. The games I commonly play are Spyro the Dragon, Spyro 2: Gateway to Glimmer, Crash Bandicoot 2: Cortex Strikes Back, Crash Bandicoot 3: Warped and Minecraft. It's a very, very hard choice to make.
I would say none of my five, and I wouldn't want the chance to play them ever again after that. The reason is because I would drive myself mad to the point of something too grim to describe on this question. I think the day I had to choose one game to play for the rest of my life and nothing else would be the day I stop playing them altogether.