[kalniel]

JKDefrag

Even the default run (just double clicking on the exe) is very effective, quick and easy to use, with good visualisation of what it's doing and no background tasks/services that hang around.

Though I also love the ability to customise and control lots of different aspects, such as different sorting routines, from the commandline, so I've set up a couple of different shortcuts on the desktop that do different things (eg. Daily C:, Weekly all drives). If you want to automate it you can then call these from the default windows scheduler.