If you're like me and enjoy spending the effort of checking stuff out (I call it "researching"

) while you're sitting around watching the tube or other inane stuff:
Additional hardware required:
2 external drives and one 8 GB USB flash drive
1. Another browser - Personally, I keep 2 additional browsers for just in case - this is the first thing I do on every new computer/OS install.
2. Bootable clone backup software, either SuperDuper!, CCC or Chronosync - use one of these in addition to Time Machine ( I use SuperDuper! only because it was the top rated pick when I got my first Mac in '06 and is still doing exactly what it's supposed to do.)
3. A separate bootable OS X installer - hence the need for the flash drive above - the createinstallmedia option is not that hard once you read it through a couple of times -
link.
imho - "everyone" should have the above 3 items in their arsenal.
4. File management -
XtraFinder and
muCommander - both free - There are some good paid apps if you are looking for additional toolsets like
Forklift and
Path Finder. (Have not used muCommander much at all since XtraFinder, but it's dual pane interface is nice to have around when you want it.)
5. File search -
FindAnyFile &/or
EasyFind quickly come to mind
Honorable mention:
WhatSize - almost required if you tend to fill your drives. There are free and other paid ones - I have them and only use this one.
OnyX - Not only is this the "only" so called "cleaner" recommended 'round here, but has some nice little utilities included when you need them. (Ex. Show hidden files without the need of opening the Terminal and a lot of others.)
After the above, it comes down to what tasks you intend to do with your computer.
OK, I think I'm done editing now....