Pretty sure Safari on Windows is dead now, so that's a non-starter.
Chrome is okay, but it's not as "light" as people like to think. You also are rather limited by what the extensions are capable of. Something like NoScript and AdBlock Plus are not possible with Chrome on the same level as Firefox.
IE is a massive security risk, and it's probably best people pretend like it's not even there. Same goes for the various shells on IE, like Maxthon. They aren't browsers, they're just different front ends on the IE rendering engine.
Opera I have used long ago and it's nice, but it seems like the developer is always kind of on a knife edge of going out of business. I like that Opera is willing to try new things, and eventually some of those ideas make it to other browsers, so I hope they stick around, but last I checked it has no real extension capability.
So that basically just leaves Firefox, or some Gecko based browser. It's not perfect, but for me, it's the only one worth considering. Chrome might well be able to unseat it if Google makes it so extensions can actually interrupt the rendering engine like they can with Firefox. NoScript and AdBlock Plus can literally prevent the rendering engine from even downloading parts of the web page. With Chrome, you are stuck with having to download the page, then the extension kicks in and reloads the page without the filtered content. Better than nothing, but given Firefox offers a far more comprehensive solution, that's where I will go.