I don't believe one should limit themselves to one.. so I have IE 6, Opera 5 and Netscape 6.1 installed.. I mainly use IE, but if a page I want to view doesn't render properly, I switch through until I get one of the browsers to render it...
I would say that I like them in the order they are listed.. IE is quick for me, and relatively stable...
Opera isn't as fast, but it hasn't crashed yet.. and I like that in a browser... who wants to have to do the whole following the path of visited links when their browsers crashes..
Netscape.. Slow, and the interface... uggghhhhhh.. thankfully you can change the theme for it and revert to a classic interface, and then its not so bad....