Although a definite bit of advice would be near impossible without knowing the specifics of your situation, it is generally agreed on that the benefits of switching between any of the 9x family tend to be outweighed by the additional cost of another OS as well as time spent reloading drivers and software.
Windows 2000 works fine as a general platform for slightly more advanced users, comfortable with the enterprise level operating system. While it can be tweaked into a good gaming system, it sacrifices performance for security and stability.
Additionally, there is the new variable in the form of XP, the next generation of Microsoft OS which combines NT/2000's heart, with enhancements to allow it to replace the 9x line. Microsoft is currently in the Public Beta stage of it's development, and you can get a copy for US$20. At this point, if you're going to try new operating systems, it really couldn't hurt to give it a whirl.