All depends on what OS you are running. If you want fast, I'd say use a text-based browser such as Lynx. I am sure there must be some similar MacOS program. But as fast as it is, many pages won't render well.

For full graphical page rendering I second the choice of iCab. It was the most recently supported 68k browser that I am aware of. Otherwise there are old IE, Netscape, Mosaic, and others.