^^^ Onyx is really simple to use and very useful utility to have. Don't worry about Disk Permissions till your mac misbehaves, however its recommended to verify disk permission once in a month. Cache cleaner is something I recommend you to use once in a week, make sure that you don't delete Cookies and your web history ( ofcourse these are personal choices ).
Drive Genius is something that you should use with little caution, I say read documentation.
Disk Utility is bundled with Mac OS and is very easy to use with loads of functions. Check it yourself, it can do a whole lot of things and its my favorite utility too.