TROTT's Theory of Browser Theology
(Disclaimer: I am using the Abrahamic Religions (Judaism, Christianity, and Islam - a wonderfully useful term I came across on Wikipedia) as the primary analogues because the UK is officially Christian. It isn't a commentary on other religions, except one which you'll see at the end...)
Firefox is a lot like one of the Abrahamic Religions. Opera, which is just as good but with some extras and some omissions compared to Firefox, is like one of the other two (it doesn't really matter which you assign; I'm classing all three as being at the same level as each other).
Safari is like an Eastern religion; theoretically just as likely to get you in the good books of however many gods you believe in, but significantly different to the "western browsers".
Internet Explorer, on the other hand, is most definitely Scientology...