#3 LOLCATS

Ok, LOLCATS (and kind of internet memes in general).

It's the inside joke phenomenon. The fact of its being an inside joke is what makes people think what they're seeing is actually funny regardless of whether or not it IS actually funny, because what's "funny" is merely the sense of self-flattery that you're in on the joke and so if you admit that it's not really funny (because, really, it's not funny, it's just stoned-nonsense-dribblings that skew retarded), well then you're not "in" anymore which means you are no longer a cool part of this cool internet meme community that prides itself on its insularity and cleverness even though really it's just a bunch of bad stoner jokes. Lolcats are retarded (cf. this from Time Magazine, via Wikipedia: "The term lolcat gained national media attention in the United States when it was covered by Time which wrote that non-commercialized phenomena of the sort are increasingly rare, stating that lolcats have 'a distinctly old-school, early 1990s, Usenet feel to [them]'").

Uch...just, uch...