There's a good choice of alternatives available now: Safari (Apple's own and the one resident on Nokia phones); Firefox (version 3 is imminent); and Opera are the three big ones. Then there's Flock, which is radically different. In addition a number of experimental fly-fasts are available: Shiira and Sunrise are the first to come to mind; and then Camino...
What to choose? Well Flock is the must-have if you're a blogger or facebook/twitter fan, and since it's built upon Firefox, Fox plug-ins usually work on Flock too--a big plus. But it's wise to never stick to one. I'm posting this from Flock, but Safari's also up-and-running right now in the background.
My hardware is an Apple G4 laptop running OSX Tiger.
Blogged with the Flock Browser