[Viridis]

"Let's Play". Name comes from (I think) the Something Awful boards. Now it's a general term for entertaining video game playthroughs.

Edit:

Originally Posted by http://lparchive.org/LetsPlay/about.html

The concept of the Let's Play thread was born on the forums of Something Awful, where they became popular in early 2006 and were given their own sub-forum in March 2007. A Let's Play thread, often abbreviated as "LP", is a forum thread where one person plays through a game, recording his progress by video, screenshots, or both, and then posts this progress in updates in his Let's Play thread. Most of the time, the screenshots and videos are accompanied by informative, insightful, in-character or just plain funny commentary by the author, making Let's Play threads a great way to get to know the ins and outs of a game in a fun way, without having to go through the hassle of actually playing the damn thing.