Yes, IE is the best or IE set the standards...

Just finish installing FireFox, things i like about it is

1. FireFox can export Bookmarks, history, passwords, cookies from IE, Opera, etc...

2. FireFox can display web site almost the same way as in IE. Opera shows web site in different way, form elements, buttons, tables, etc...

For now i plan to use IE and Opera only as i don't need to use 3 browsers at a time. Opera is good for casual browsing (i think it fast too, can also set not to load images in a single click, back button works fast - caching).

IE is required for viewing some sites. Eg: gmail.com