I've been using Firefox for quite a while now. Before that I used Netscape, and I still use it when I need to create or edit a web page. I'm linking to the Netscape Browser Archive because, when they came out with version 8, I think, it was just a browser. I like the complete Netscape package - browser, email, and composer. Those people who never create or edit a web page don't need the composer, so they don't really miss it. I haven't upgraded since version 7.1, and I probably won't. I appreciate that they keep the older versions available here so that you can download and install the version that meets your needs.
I know there are people who use that browser that comes with their Windows operating system, but I refuse to use it. There are a few times I have to open it to see what a web page looks like in IE, but I even try to avoid that. Usually I can assume that, no matter how nice the page might look in any other browser, it is going to be messed up in IE. I don't know why that is, but it irritates me to no end, and I usually don't know how to fix it.
In Firefox, I have the IE Tab extension installed so that I can check things, without opening that other browser. That's pretty handy. There are over a thousand useful add-ons for Firefox, making it easy to customize your browser and make it do what you want. Usually I just start browsing and installing the ones that interest me, but today I found this list of the Best Firefox Extensions - compiled and broken down into categories. Each one has a brief description of the extension and what it does, and the link to download it. Instead of having to browse through endless extensions trying to find the right ones, you might appreciate starting with this list. I'll be going through it to see what great extensions I've missed and don't have yet.
Also, in the future, I will be listing my favorite extensions here, too. Maybe I like some that haven't made this list.