All F2P games give +1 games and +1 exp now. Doesn't work anymore.

If you wanna add them all to your account quickly and easily. Log into steam with the browser and run this from the store page. http://pastebin.com/ENuNZsyw just copy paste it into your browser console and hit enter. Now you have all the F2P games on your account. This is for people that like hoarding games or if you want a little free exp.

Enjoy!

-IMPORTANT EDIT. Valve seems to have patched F2P games from giving EXP. I still have all my games for now. I suspect they will vanish at some point though. User lunboks was kind enough to post a script to remove free licenses on page 4. You might still need to remove some manually though.