I've tried a lot of browsers over the past few years: Firefox, Chrome, Safari, Opera, Camino.
Frankly, I really don't understand where all this popularity for Safari is coming from. The extensionsystem sucks, it still can't remember my last session (yea, I know you can go to History - Restore last session but I want that when it opens), it gets very slow after a while and I think it really loves watching the beachball spinning around on my screen.
I've tried different versions of Opera over the years but it still doesn't feel right. I can't really say what 'it' is but it just doesn't.
Firefox was my main browser most of the time. It never let me down, never had any real problems with it, it was fast. Tried Camino but Firefox felt better.
Finally I tried Chrome and since then (for about 3 months or so now) I've been using it all the time. It starts up fast, it loads everything fast, if a plugin crashes it doesn't crash your browser and if a webpage acts up it neither crashes your browser but just its own tab unlike most other browsers. One thing they could improve is how they organize tabs though :').