The browser I found most useful for my need is opera. Here are the features that I really like about opera: its an email client, a file sharing client, stream and share music to your friends who are also using opera, pop ups will be opened in a new tab instead of new windows, you can group tabs (most useful feature for me), save sessions, and its interface is highly costumizable.
I also use firefox for seo purposes and for the addon firebug.
Google chrome, if I need speed. It can also run flash content w/o flash player very handy since I dont install flash.
Ok, I gotta tell ya. My favorite browser WAS Chrome. Yes, it's less secure than FF but it was always easiest for me with multitasking at the level I do and I found it much more simple. However, there's a browser I have just discovered that's just about the equivalent of the usability of Chrome with seemingly most, if not all of the security of FF. I'm just about to say it's my FAVORITE. It's a Mozilla browser named Aurora and it's pretty darned good and uses many of the same add-ins of FF. You really ought to give it a try. :top: