On my main PC Laptop I've got Firefox 11 "Aurora" (beta of the beta
), Internet Explorer 9, Google Chrome, Opera, Maxthon 3, Avant, Netscape Navigator 9 (based on Firefox 2), and Safari.
Why? Because I need to check to make sure that the websites I make for my clients are compatible with at least all the major browsers (Firefox, IE, Chrome, Opera, etc.) and hopefully the minor ones (Maxthon, Avant, etc.)
For general internet browsing I use Firefox. It's the best IMO
What about you?