Programs That Every Computer User Should Install

Well I have compiled a list of programs which I believe, no matter what your computer experience, should be installed on your PC..

So there are three different free anti-virus programs that received high ratings, and all three are good enough to abandon your high-price anti-virus software
Avast --My personal preference
Avira  --Make sure you pick the right site (I just download it from download.com), some say that it is annoying.
AVG   --Nice quality, but once again, my personal preference is for Avast
... and I don't know why they all start with av

Another program that should be installed alongside almost any anti-virus program is ThreatFire.  This program analyzes program activity, rather than virus signatures, to detect viruses, so it performs magnificently against new threats that haven't been seen by your anti-virus company yet..

So I have two favorites, both from Piriform, that will help you manage your hard disk space
CCleaner--Cleans up your hard drives, deletes temporary files, etc.  Also cleans up your registry. 
--Note:  when using CCleaner, remember to only have it delete stuff you know you want to get rid of.  If you're not sure, un-check it.
Defraggler-- I personally prefer this over the Windows Defrag tool

All right so there are four main browsers that you can get:
Interet Explorer --My least favorite, slower than the rest, less customizable, however it is still generally the industry standard for browsers
Firefox --My personal preference, small, fast, and very customizable, with add-ons galore
Safari --Apple's browser, small, fast, and I have never really used it so I can't say any more
Opera --Open source browser, been around forever,
Google Chrome --Google's browser, fast, small, different layout than the rest, with some interesting goodies including HTML5

Some addons worth looking at:
AdBlock Plus --Blocks all of those annoying ads - main reason that I haven't switched to Chrome
Cookie Monster--Lets you control how cookies are handled
Vacuum Places Improved-- clears out LSOs (aka Super Cookies)
Greasemonkey --Allows use of custom user scripts.  Install it after you've found some scripts that you want implemented
FasterFox --Makes your browsing Much faster
FastestFox --I like some of the stuff that it does, like when you select text it gives you a little button to press to google/wikipedia/youtube/etc it

So there are basically 2 options for full-featured productivity suites

OpenOffice.org --Free open-source productivity suite courtesy of Sun (the guys that made java) with just about as much functionality as M$ Office, and can handle most MS Office files, however, in my opinion, nothing beats Excel

Microsoft Office --Fairly expensive ($150 is as cheap as it gets, I believe) but has a whole ton of features and slightly outperforms OpenOffice.org. 

Some more that I just thought of
7-Zip -- Unzips just about any archive file you can throw at it (tar.gz, .zip, .rar, .7z, .ace, etc...)
SpaceSniffer -- Gives a nice spatial representation of everything on your hard drive, great for finding out what ate all 500GB of hard drive space...

In case you're doing a fresh install, don't forget java, flash, and acrobat reader.

Make some sort of schedule (paper or automated on the computer) to run CCleaner, Defraggler, and your anti-virus program of choice.  This can speed up your computer and keep it running speedily.  And feel free to comment about any apps/categories I should include.