PerfectDisk Disk Defragger
When visiting the PerfectDisk Web site, I even saw the graphic saying "See Why Foster's Chose PerfectDisk". No, they weren't talking about me. It references the Australian beer company that shares my name. In addition to all the ways that it arranges my data optimally, I really like that I can schedule it to run in the middle of the night once a week. That way it speeds up my computer when I'm sleeping. You can download a free trial and give it a try yourself. If you like it, you'll find it is reasonably priced.