3Dmark2000 is an excellent benchmarking utility as long as you're interested on comparing how well certain features are implemented on different video chips. However, the 3Dmarks score, being just a weighted average of two "game" benches, is useless since it doesn't represent any real-world situation.
As a thumb rule, the best benchmarks are the programs or games you use the most. I'm sick of video (and CPU) reviews posting just Quake III scores like it's the only game on the face of the Earth - several months ago it was somewhat justified as Q3 was the technologically most advanced title with which future performance could be projected, but that doesn't apply anymore.