Great sequels in 2000 - Baldur's Gate II, Thief II, Diablo II
Great new games - Deus Ex, Majora's Mask, Hitman: Codename 47, The Operative: No One Lives Forever
And I would easily pick Deus Ex as the best and my personal favourite game from that year, and one of the most influential FPS-RPG hybrids - if it was any other year.
Cause this is the year that The Sims launched. And Sims were just something really different, not only a great game with a lot of innovations, but one of those Blue Ocean games that attracted new players and made a new market, something like what Myst did a few years before it. Actually, Myst was best-selling PC game until The Sims, which went on to sell 6+ millions till 2002, settling at around 11+ millions by 2015 on PC alone (with 15+ millions total).