Firefox, I find it the most efficient and stable, with the largest variety of security plugins. Plus, I don't like the idea of google following me around their browser.
Ignore the ones that say they are safe from brute force hacks, every browser is, is it is even sorta new. As of now, you can only effectively brute force the key if it is under 80 bits in length, and even crappy WIFI firewalls are 128 bit.