PC Magazine has a list of recommended free software. http://www.pcmag.com/article2/0,2817,2271644,00.asp
It's freeware, but not necessarily Open Source. I would not have picked all the things they pick. I especially hate the Google Toolbar. I've found it to be clunky. It takes up too much memory, slows things down, and is always, ALWAYS, collecting information about how you behave online. That's the part I hate the most about it.
I intend to check out the Maxthon browser right away ...