A "classic" game is any game you remember fondly from those days when not having a job and living in your mom's house made you a normal human being rather than a pathetic loser. If your idea of a "classic" is Doom, Ocarina of Time, or anything with a real-time perspective view and more than a handful of 3-D polygons, you are just too d*mn young, and I hate you. Or rather, I will start hating you, as soon as they finish moving me out to the Old Programmer's home.
And for the record, my favorite classic games include "Ultima IV" and "Legacy of the Ancients"