Firefox, Firefox, Firefox, Firefox…
I’ve been using Firefox for over 9 years, all the way back to early 2003 when it was called Phoenix.
And somewhere around 2004 / 2005 Firefox, (then Firefox 1.1) was pretty much my primary browser.
The only time I used anything else was when I ran into a site that could not be viewed using the Gecko engine, which was an issue at the time.
I currently use Firefox 10.0.2
And am testing Firefox 11.0