Wiix, I only use Firefox. It's great for me. I actually got rid of IE altogether but I wouldn't advise doing that. I think I have some problems with downloads because I'm only using Firefox. Just double check what you're downloading before you press the button. Some downloads come with google packs and other things. If you're doing it for the first time, you might want to make it as simple as possible.
http://www.mozilla.org/download.html