Given my overall ignorance of computers, and what I use them for, I could probably use any browser and be happy, or at least not tear out my hair frustrated.
However, I got hooked on FF during the time of my addiction to the browser game Ikariam, adding in just about every illegal add-on I could find via greasemonkey to make things easier for me in the game. (And they're only "illegal" in the sense that most of them just replicate stuff Gameforge wanted you to pay for, but whatever. I was able to quit, so that's that.)
I installed Google Chrome and liked it, in the sense that pages seemed to load faster, but disliked it vs. FF in the sense that I started seeing lots of ads again for the first time in what must have been months. I found that so irritating I just couldn't stick with Chrome. So, until somebody comes up with something like adblock for another browser its going to be FF for me.
My only b***h about FF is that I seem to get these weird messages about FF being "already running, but unable to open" fairly frequently, especially on my desktop, a bit less often on my laptop. And then having to restart the machine to get FF working again. Both my machines are pretty much vanilla Vista, so I'm probably beyond help anyways. 
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"The man who has fed the chicken every day throughout its life at last wrings its neck instead, showing that more refined views as to the uniformity of nature would have been useful to the chicken." ? Bertrand Russell