Although I’m in the minority, my go-to browser is Firefox. One of the chief reasons is privacy. Firefox is usually the leader in introducing privacy features into their browser. The recent introduction of SmartBlock is an example of that. Basically, it short-circuits third-party tracking scripts. This allows pages to use those scripts to work properly without actually passing information.
One of the arguments against Firefox is that it is slow (which isn’t really true). Maybe this will help address that percieved slowness.