Firefox for me.
I did try Safari, but one thing that really niggled me was the maximize button didn't take my browser full screen. I like my browser full screen, so had to manually resize it...that annoyed me a little.
That and a couple of other things, can't remember what (Firefox plugins being one...Didn't know there was a Safari Adblock).
I also gave Camino a try, and the UI was much nicer than Firefox I thought. It had a couple of niggling issues too, so I uninstalled it....for the life of me I can't remember what they were though.
So I'm a Firefox user again (diehard firefox on Win before I went Mac anyway), with the occasional flit into Safari for sites where I have two accounts and need to switch temporarily.