I won't recommend ticking all, because it harms performance rather than make it better.
One reason for not ticking everything is convenience. If you tick everything, all your password, user names etc will no longer be there. This isn't a problem for those with good memory, but for those who have bad memory, it is a no-no.
Second reason is because of prefetch. While prefetch takes up hard disk space, removing it is detrimental to some PCs, to some extent that it can take up to 10 minutes for a PC to start fully.
The last reason is customization. Those who are tech-savvy enough to customize the PC will find all your customization gone and needing to re-customize everything again.
These are the boxes that I ticked (ticking the Prefetch box is optional):


And never do anything to the registry unless you know about Windows registry. Some can be removed without problems, but most aren't.
For those who don't like unknown cookies or advertising cookies lurking around, CCleaner can manage it better.
