I've been reading Homestuck for a while now. Good lord. It's one of the most amazing things I've ever read, on or off the web.
It starts out as a parody of text-based adventure games, and then just keeps running with that format to get bigger and better.
It's also got a bunch of cool flash animations interspersed to spice things up, and a dedicated music team to create the soundtrack for everything.
I you do end up reading this, let me just tell you now: Read everything. Skip nothing. Don't skim the "Pesterlogs". Don't pass over the intermission(s). It's going to take a long time to get through the archive (I think it's currently the longest webcomic in existence, and if it's not yet, it will be in a few more months), but it pays to read, see, and know everything you possibly can about the story. Don't get lost. Everything will make sense, in time.