So as not to clutter up the twilight discussion...
Homestuck is a webcomic (the term "comic" is used loosely, see below) by Andrew Hussie. It's about...well, it's about four kids who decide to play a highly immersive game. I can't really say any more without massive plot spoilers, but hey. I think it is quite excellent, despite moderate (full disclosure, male here) genderfail. It is funny, sad, and very, very awesome.
The comic is written in the second person and styled after a text adventure game (Colossal Cave, etc). It consists of about 4000 pages, which can be divided into the following types:
-A single .gif or still image accompanied by up to a paragraph of narration
-Multiple stills, or stills and a single .gif, with some narration
-One or several stills and .gifs with anything up to <em>several pages</em> of chatlogs (the main source of dialogue)
-A short interactive flash (all possible options can be used in about the time it takes to read longer narration)
-A short animated movie (usually ~3 min)
-A long, detailed interactive flash, which will take up to an hour to explore (There are six of these as of this writing)