98/2k dual boot are good options. Stay the hell away from ME, tho. Total shit of an OS.
XP is good, but it still could use some fine tuning. Service Pack 1 should fix a lot of lingering issues.
If you're planning on a dual boot, let me offer some sound advice: Install 98 on your C: partition, and 2k on your D: partition, and install 98 first, along with all the updates, before installing 2k.
You won't hose your system installing 2k first, but you'll have to jump through a hoop or two to dual boot. This is due to the fact that 98 will over write the boot sector so you can only boot to 98, and then you have to "repair" the 2k install to fix it.
Oh, yeah, keep everything FAT32 for best results. 98 can't read NTFS, unless you shell out big bucks for a read/write utility.