i like chrome when i'm using windows (which is not too often anymore), but i still prefer the customizability of firefox. Maybe once chrome makes it out of beta, there will be a decent selection of plugins and add-ons.
I've tried Firefox numerous times and I've always ended up back with Safari. I'm not a big plug-in buff, and of the extra button in Firefox bug me. The UI of Safari is much cleaner and more simple, and with 1Password, it's just as secure. And I've always found it faster.
Actually one of the most important reasons why I use FireFox is because I play an online game that uses an online launcher. In order to play it, I have to go to their website and launch it from there, Safari doesn't support that, only FireFox and Internet Explorer do.
I did use Safari on Windows for quite a long time though, and I can say it's awesome. But it's really weird in some websites.
FireFox does crash on my desktop computer sometimes, but on my laptop it doesn't at all. It's probably because of malwares, my desktop computer is injected with many spyware and malware, I'm sure that's why. Anyway, I've tried Chrome before and I totally hated it. It crashes on many websites, and it displays some websites in a very weird way, just like the oldest Internet Explorer that comes with Windows XP does lol.