Get an external backup drive and start using SuperDuper. That's about it.
What else I have installed in my Admin account, for reference...
- Onyx - never use it
- ClamXAV - never use it
- Mac Freeware Update - This isn't really all that close to perfect, but I do actually use it.
I think that's everything I have that could fall into this category....
TechTool Pro, Drive Genius, and DiskWarrior are all good utilities. They differ in what they do, though they're all centered on repairing drives.
There are plenty of times when Disk Utility, something included with Mac OS X, can't fix a disk problem and you need something more. Those utilities are usually able to correct those kinds of problems.
You really don't need anti-virus software unless you're in business and dealing with a lot of Windows users where you might pass on a virus in a file that's been passed to you.