I use different browsers for different things. My desktop is 11 years old (554mHz Celeron 2 processor, 512K ram. with windows ME upgraded to XP professional - Archaic dinosaur!) and for some reason Firefox is really slow, so I use Chrome on it. On my laptop I use mostly Firefox (that's the one I voted for in the poll.) I like Opera if I'm on a slow connection. The Turbo boost is blazingly fast and I love the speed dial feature. I also prefer Opera when downloading torrents, though I "open" the torrent with my uTorrent client. I have a bunch of "toolbars" on Explorer and only use that when I'm want to use the Toolbars.
Sometimes I'll use Safari just as a change of pace, but I really see any advantage it has over any of the others.