Open source, you can add tweaks and mods easily if you wish
Useful extensions to do just about anything you want or need or dared to dream of
Updated fairly frequently
Faster
Doesn't allow ActiveX to molest your computer
Lots of themes for customizing appearance
Not evil
Bill Gates probably uses Firefox when he thinks no one is looking
Internet Explorer:
Created out of antimatter in an evil universe from beneath the Dark Side
Seriously though, in this and many other forums one of the first recommendations made to people who have had to clean malware off their systems is to switch to Firefox. The only thing IE is used for by most people now using Firefox is for downloading Windows Updates. There is now a site for downloading Windows Updates via Firefox but the jury is still out on whether it's a good idea to use it since it's not an official MS source.
Thanks agumon, I try to be funny be without coming across as stupid or annoying...
One thing people say makes Firefox more secure is that it won't run ActiveX which a lot of malware uses to get into computers without being noticed (until it's too late).
I think maybe Internet Explorer would be more secure if it was easier to understand what settings to use for security like on "Intenet Zones," ActiveX, Privacy, Advanced, etc. It seems like they're set too low and malware gets in but if you set them higher there's a lot of pop up boxes always asking if you want to allow this or that to run. And since it's used on over 90% of computers it attracts the most attention from the idiots who create malware.
But my favorite thing on Firefox is that you can use the Adblock and Remove This Permanently extensions to get rid of all the annoying advertising that moves around and flashes on and off to distract you all the time.
It seems a lot of people like Opera (especially now that it's FREE!) but it's so different from IE or Firefox it takes a while to get used to.
Hmm, well it does appear to be quicker, but, you can't get the ebay toolbar installed onto it, which is annoying, or I'd let my whole family use it (we all use the same user as my parents may need to quickly hop onto the pc withough switiching users).
So currently, I use Firefox for the majority of what I do (especially downloading - its much quicker), but the rest of my family use IE.
Oh, and somebody mentioned about all the extensions, I have to admit, it is annoying that there are som damn many, I'm gonna test FireFox as much as I can tonight and see if it does need any.