Well was looking through the forums and forgive me if someone posted this already but was actually surprised, sites like the Escapist and Gamesindustry would post up other charity events but not even pay lip service to the biggest charity marathon in the speedrunning community?
At any rate for those who don't know every year Speeddemosarchive and SpeedRunsLive put on a combined week long non-stop gaming charity marathon known as Awesome Games Done Quick (AGDQ) for the Prevent Cancer Foundation (PCF) with AGDQ 2014's goal being to raise $500,000. The goal was easily met and the donation total went past 1 Million dollars just before the main portion of the stream ended. Currently the bonus stream is in effect, and the donation total at time of writing sits at: $1,020,430.47 from 18,246 different donors. There is also a smaller sister event that takes place during the summer aptly named Summer Games Done Quick.
If you want to do some further reading I will post up some links below.
Awesome Games Done Quick stream: http://www.twitch.tv/speeddemosarchivesda
Games Done Quick Page: http://gamesdonequick.com/
Speed Demos Archive: http://speeddemosarchive.com [This currently redirects to the GDQ page until the marathon officially ends]
Speed Runs Live: http://speedrunslive.com/