I don't think the question is answered appropriately by a popular vote. Security isn't really a static two dimensional issue, as each browser has its own weaknesses that change with ongoing updates and newly discovered 0-days. Today's bulletproof browser might be a bucket of fail next week.
People are blinded by MAINSTREAM BS and its sad!
True everywhere.
I recommend multiple browsers, one dirty preferably well sandboxed browser, and one for more sensitive stuff. From there I choose by performance and features rather than it's historic reputation for security.
I have 4 browsers and here's what I use them for:
IE9 - Testing web design to see how bad things look in different versions of IE, also for MS proprietary coded sites.
FF - Nothing really unless I want to try something unusual(there's a plugin to do any thing you can dream of) "browse as googlebot" comes to mind.
Chrome - My dirty browser, it renders everything correctly (even a lot of sites coded explicitly for IE) , is fast, updates all the time, has plugins for security features I like, I'm impressed with their bounty system for finding security bugs and aggressive update cycle. I'm not all that worried about the privacy stuff because my private things don't happen in this browser.
Opera - My clean browser, I only use for trusted sites, has many features I like, plugins too.
From reading the comments of the poll, I discovered Commodo Dragon, sounds pretty interesting and I might make that my dirty browser.