Homestuck is a story told via pictures, words, movies, music and games. It started out as a webcomic, but has now transformed into being what seems to be a new form of media. Some have described it as interactive fiction.
I originally came to Homestuck after finishing the cult JRPG EarthBound, for which Homestuck was named, and wanting more. When I first began, I was weary of what I thought might be internet wackiness for the sake of wackiness: a stew of pop-culture and in-jokes mashed together into what is wrongly called postmodern. And the story does contain that: this is a story in which Betty Crocker attempts to take over the world with the help of The Insane Clown Posse. A story in which a prop from the movie Con-Air is a central figure. A story in which a fictional MMORPG based off of the unsuccessful movie GhostBusters II is played by a group of characters. The amount of references to pop culture and internet culture is staggering, and remains to be cataloged. This is a work of irony that has launched many internet memes.
But it is also an intricate and deeply-plotted work, medieval in its symmetry and dedication to symbolism. The four characters we first meet are each symbolic of a classical element, and the next twelve characters we meet are meant to symbolize the Zodiac. The universe that the story takes place in has an intricately layered cosmology that seems to be based on gnostic or neo-Platonic symbolism. The story is ongoing, and what the symbolism all adds up to is unknown, but it is a sign that the story, despite its amusing trappings, is not just a collection of jokes and digressions.
So is Homestuck good because it is a postmodern pastiche of internet culture, or because it is an epic work of cosmological explication with classical trappings? The answer is, neither. Although all of that is interesting, what brings me back, and what made me wade through the story's duller moments, is the realism of the characters. No matter how fantastic and convoluted the story gets, the characters, and their dialog, always seem real. Angry but loyal Karkat, sarcastic and wordy Dave, earnest and friendly John, Spacey Jade, straight laced and poised Kanaya and selfish and pretentious Eridan all come alive in the story, and I always feel that the description of the characters respects them as characters in their own right, no matter how the plot twists and turns. The dialog just captures the characters' voice wonderfully, and even pages of dialog fly by as the characters go off on tangents, stretch metaphors, and work around their romances and rivalries.
It isn't always an easy read, and it is hard to get into at first, but many people have found themselves just as taken with Homestuck as I do. I would suggest that everyone give it a try by starting here.
Update 2016: After seven years, the the last three of which were marked by an increasingly irregular update schedule, with several gaps of months between updates, Homestuck finally concluded on its seventh anniversary,
April 13, 2016. The ending was generally agreed to be technically superb while still leaving many of the character and narrative arcs in a puzzling state.