Another stupidly good year.
My pick goes to Halo: Combat Evolved. While Bungie improved upon multiplayer in the years after 2001, it never eclipsed the single player campaign from the first game. It’s still the best FPS campaign ever made, in my mind, due principally to its amazing improvisational gunplay.
Halo is a lot like Super Mario 64 — a revolution in the console space but also a near-perfect game without factoring in its historical significance. Even in 2001, one of the best years for video gaming, it ranks on top.
My second pick would be Ico. I love that game dearly.