"Best" is a word thrown around quite freely nowadays. Often times, it refers more closely to popularity than quality. But here we are, with a complete year-by-year breakdown of the "best" movies since 2000... according to critics.
Whether you choose to agree or disagree with them is another matter entirely (an audience score has been included for comparison). And given how these critics have leads us astray lately with acclaimed dumpster fires like Star Wars: The Last Jedi, I wouldn't blame you for being skeptical. In fact, a few of these selections are rather questionable (can we please just get off Boyhood's dick? It's pretty much all gimmick...)
Anyways, check 'em out.
2000: Crouching Tiger, Hidden Dragon
Critic score: 93/100
Audience score: 8.1/10
2001: The Lord of the Rings: The Fellowship of the Ring
Critic score: 92/100
Audience score: 9.1/10
2002: Spirited Away
Critic score: 96/100
Audience score: 9/10
2003: The Lord of the Rings: The Return of the King