Chrome is pretty much the best
opera >>>> ie, imo, though ie has come a VERY long way, i admit, since they don't have a monopoly on windows browsers anymore...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
Chrome will eat even more. Each separate tab is its own process.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.