Is there any defrag program with markedly better defragging skills than the built-in XP/2000 one(s)?
Contig + PowerDefrag. Basically, it runs Contig on every file in the system, then runs Windoze defrag after. Works quite well. Give it a try... it's free, and less than 500KB total to download.
ContigPower Defragmenter GUIUnzip both to the same directory, then run Power Defragmenter GUI.exe , and select the PowerMode Disk Defragmentation mode.
If you want, you can also use
PageDefrag to defrag some system files that are normally not able to be modified (eg, pagefile, hibernation file, registry, and others).