Chrome is pretty much the best
my quad core processor makes light work of firefox's supposedly slow startup time. chrome's incognito browsing is better for porn/terrorist activity/hiding your ability to cook though
also my firefox has a cooler skin than any google chrome will ever have by virtue of better (read: more familiar) interface
ie gets a lot of hate because of how bad ie6 and previous incarnations of ie were. i'd say it's still the worst of the 'big three' but it is a solid choice if you can't get firefox or chrome. ie9 is much improved
I use firefox because it's got some cool add-ons and I like the layout but it is a bit of a memory hog so I keep saying I'm going to switch to Chrome some time.