I am also an avid Firefox user/supporter. Firefox is the safest browser out there. They are updating the browser constantly so their security is top notch. Also, the variety of add-ons is superb.
Persona's - an excellent way to customize your browser. Choose from 30,000+ "skins" that let you make Firefox fit your own style.
Zotero - for those of us that do a lot of research or writing, Zotero helps you collect, manage, and cite your research sources.
Adblock Plus - pwa89 mentioned this above, and it is worth mentioning again. It makes surfing the web so much better looking and easier.
Forecastfox - an awesome weather add-on that integrates your local weather forecast, including severe weather alerts seamlessly into the bottom bar of the browser.
Easy YouTube Video Downloader - You know you have seen videos on YouTueb you just needed to have on your computer to watch over and over again. This add-on is made just for that.
ReminderFox - a little add-on that lets you set up ToDo lists that alerts, and alarms, right in your browser without the need for a separate calendar program.
You get the idea. I think that FireFox is the most versitle browser out there. If you go with FireFox, I promise you won't be disappointed.
www.firefox.com
By the way, I use all of the add-on's listed above :)
Last, on a side note, I do not and will not ever use Chrome. I love Google but in their Terms and Conditions, they were a little bit tricky with their wording. Basically, when you agreed to their Terms and Conditions, you were permitting them to record and store every site, any media, basically anything you did through Chrome, on their servers. So, your browsing experience was being recorded and kept for their personal records. I found that invasive, hence I don't use or recommend Chrome.