Keeping your PC clean and efficient

A while ago I found an article called Top 12 Ways to Degunk Your PC, which explains how the Windows registry gets cluttered with unnecessary data, old program references, and so on. One of the products mentioned by the article was Registry First Aid. I've found a better one: CCleaner.
It's better in two important respects: firstly it's freeware, and secondly it cleaned up a whole load of entries on my PC that Registry First Aid didn't find. Also, removes temporary files, cookies and other miscellaneous bloatware. It's fast and efficient. One of the nice features is that you can add a menu item to your "Recycle Bin" that either opens or runs CCleaner, so it's right there when you need it.
This is a screen shot of the program, showing some of the cleanup options available. It's also aware of browsers like Opera and Firefox, and can clean out the cache from those programs too.
Another program I have been evaulating is Uniblue's Registry Booster, which claims to be able to defragment the registry, and costs US$29.95. The jury's still out on whether Registry Booster is worth the money or not, or even whether it is posible to defragment the registry.
Update: It's not worth the money. Rather use NTREGOPT and PageDefrag.

Download CCleaner from their web site or from Downloads.com | Get Disk Cleanup to work faster