Soundozer - it's kind of like Pandora, but you can listen to any song you search for and you can create a station based on that song. You don't have to register either.
Free Rice - Answer vocabulary questions and rice is donated to charity! Be sure to turn off adblock when using this site, as that's how they supply the rice!
Mendeley - The best free way to manage your research. Organize, share, discover. Great for when writing a paper, it manages all your referencing/bibliography in many different available notations
Self-Help/Advice:
7 Cups of Tea - Free, anonymous, and confidential conversations with trained active listeners. Please don't spam the site, they offer a great service
Thrive On- Not completely free, but aims to bring affordable online mental health programs to those who would otherwise go without. Starting next month
Blah Therapy - Online listening service. "Experience the rewards of venting to a stranger or lending an ear."
MoodGYM - Learn cognitive behaviour therapy skills for preventing and coping with depression.
Social Services; resources - a subreddit created by a professional Social Worker who has spent a career procuring resources for those in need.
Portable Apps - load several apps on a thumb drive to run on any Windows PC
SlimDrivers - Cloud based program that detects what drivers need to be updated. Incredible--especially after formatting an operating system. No need for CDs or trying to remember which model card, adapter...etc. you have
Paint.NET - Windows application designed to be the much needed upgrade to MS Paint
Pixlr - Online photo editor. web-based equivalent to an old version of Photoshop from 2005 or something. Very functional for occasional use manipulating images, and seeing as it's web-based and doesn't require an account it's super easy to use from anywhere
Sumo Paint - Powerful graphics editor for your web browser and pc
Blender - Open source, cross platform suite of tools for 3D creation
Audacity - free, open source, cross-platform software for recording and editing sounds
MuseScore - Free music composition and notation software
Notepad++ - a free source code editor and Notepad replacement that supports several languages
Sublime Text - a sophisticated text editor for code, markup and prose. Note that it is a never-ending free trial, but you should consider paying for the service to support the developers
Sublime Text ColourCoder - this plugin for Sublime Text will highlight every variable in its own, consistent color (feature known as semantic highlighting, variable-name highlighting, contextual highlighting) you name it
Atom Editor - A hackable text editor for the 21st Century
Komodo Edit IDE - Powerful free editor for Python, PHP, Perl, Ruby, Tcl, Javascript and other major web languages
CeltX - Free scriptwriting and all-in-one production studio
Rainmeter - Windows desktop customisation. Similar to Conky for Linux
LibreOffice - offers much more up-to-date software than OpenOffice
TeraCopy - designed to copy and move files at the maximum possible speed. It skips bad files during the copying process, and then displays them at the end of the transfer so that you can see which ones need attention
Privacy Badger - developed by the EFF (Electronic Frontier Foundation) and is a browser add-on for Chrome and Firefox that helps lower your internet footprint and stop third party trackers from following your movement around the web
DistroWatch - Put the fun back in computing. Use Linux, BSD. This site gives detailed information on each Linux distribution and provides links to their respective communities
UNetbootin - allows you to create bootable Live USB drives for Ubuntu, Fedora, and other Linux distributions without burning a CD. It runs on Windows, Linux, and Mac OS X
Spoon - Use your software and files from any desktop. free virtualization startup that lets users launch full desktop apps from any browser without having any of them installed on my computer