r/letsplay is a community for those who record gameplay with voice commentary, usually while playing the game. This content is typically uploaded to YouTube or livestreamed on Twitch.
Ooh, I think the first Let's Play series I watched on YouTube was a dude playing Demon Souls. He went by EpicNameBro. I haven't thought of his content in quite a while and didn't realize there was a community that did the same style of content.