You'll get a lot of varying opinions here.
Firefox is the best for my own purposes. I'm an add on junkie, and I have yet to see the variety and quality of the add ons replicated in any other browser ecosystem. (I use Noscript, AdBlock Plus on certain sites, and Ghostery as a selection of my addons)
So get Firefox if add-ons really matter to you... 13.01 is the latest stable version i believe.