I’m in my 20’s and I’ve played video games for roughly 18 years or so. I’m terribly biased in favor of video games made in Japan when it comes to my tastes. I attribute this mostly to the particular aesthetics and utter disregard for the limitations of reality that seem to be really characteristic of Japanese developers.
The Super Nintendo Entertainment System (SNES) is my favorite video game platform of all time. The Playstation 2 comes in a close second (I’m counting PS1 backwards compatibility here).
My favorite video game of all time is Super Mario RPG: Legend of the Seven Stars for the SNES. The second might be Tales of Eternia for the Playstation. I’m not too fond of ranking games in a rigid manner.