Never use anything but Fox 5, unless I go to some web page so backward it won't even work in a Firefox IE tab. Necessary add-ons are Speed Dial, IE Tab, Old Location Bar, and PhotoBucket Uploader.
IE 9, 64-bit, was faster for video streaming, but it got my old CPU too hot-and-bothered. It's the first IE I've liked, since I found the fox.
Chrome never made any sense to me.
Opera is pretty.