Homestuck is basically a silly webcomic that happens to be more lengthly than the fucking Old Testament and New Testament put together. Prominently featured in the story are shitty memes, spooky plot shit, and time shenanigans. It's difficult to encapsulate what exactly Homestuck is in a single paragraph, since it's just become so unwieldy and complicated over the years it's been running, but basically it's one of the best things on the internet.
It's also one of those things that unfortunately has little appeal to those not already wrapped up in the story; sitting down and reading this webcomic will take you an enormous chunk of your life. And you'll likely have to read it multiple times in order to really understand the plot, because my god, it is as complicated as it is nonsensical and idiotic.
Homestuck has a total of 7955 pages, 14691 panels, 812424 words (162 [S]s, 3h38m44s)
You should read this because the music is really good (yes, you read that correctly. the webcomic has an extensive official soundtrack) and the story is enjoyable and never takes itself too seriously.
http://mspaintadventures.wikia.com/wiki/Homestuck