I've used IE6, Netscape7, Opera and Mozilla but the fastest, smallest browser by far that I have found is at
http://www.flashpeak.com scroll down the left side to Freeware and you will see the Flashpeak Slim Browser. It has a layout similar to IE but many other useful features too.
As mentioned have given all the above browsers a fair go on a high speed connection and on a 56K modem and so far the Slim Browser beats them all. No, I don't have shares!