Evolution of Dance (April 2006) One of the first YouTube memes—"Numa Numa" and "Star Wars Kid" predate the site—"Evolution of Dance" remains the most viewed YouTube video of all time. And it's only one man, Judson Laipply, dancing his heart out to a series of pop songs. The video remains a testament to the power of dance — and of making an ass of oneself onstage.
Lonelygirl15 (June 2006) Not all memes are 100 percent organic. Prolific YouTube user Lonelygirl15 was eventually outed as a product of technology company EQAL. Let's be honest: her videos were never particularly interesting, but they raised fascinating questions about reality and identity and being cute online.
Chocolate Rain (April 2007) You can't force Internet magic—you have to just let it happen. Tay Zonday had everything going for him: an overlong original song, nonsensical lyrics, a Muppet voice, and improbable sincerity. We still don't know what "Chocolate Rain" means, but Zonday's dulcet tones continue to delight.
Charlie Bit Me (May 2007) An early instance of a YouTube video that forces you to ask, "Shouldn't their parents intervene?" But "Charlie Bit Me" is really harmless fun, with two precious kids attempting to out-adorable each other. The fact that there's an English accent involved ups the cute quotient immeasurably.
Obama Girl (June 2007) In a time when we were all becoming more politically active—you know, putting new stickers on our Facebook profiles—Obama Girl took a stand. She had a crush on Obama. Really, who didn't? But Obama Girl sang about it on the Internet, and for that, she's marginally more famous than the rest of us.
Keyboard Cat (June 2007) While "Keyboard Cat" entered the scene way back in 2007, his status as meme didn't emerge until sometime last year. That's when the piano kitty started appearing everywhere, playing other memes off with that trademark "Keyboard Cat" sound. By now, he's wearing a bit thin, but try to watch the original without cracking a smile.
Leave Britney Alone (September 2007) If we learned anything from Chris Crocker and his scary passionate plea to "Leave Britney Alone," it's that YouTube fame isn't forever. There was talk of giving Crocker his own TV show, but that died around the time his tasteful nudes surfaced. Luckily, he continues to live on in our hearts.
Justin Bieber (late 2007) That's right, the Beebs got his humble beginnings on YouTube. He was discovered, apparently, or pop star-manufactured if you're more of a conspiracy theorist. Either way, he's a reminder that Internet celebrity can transition to the real world. Yes, even if you're Canadian.
David After Dentist (January 2009) And you thought "Charlie Bit Me" was morally questionable. Don't worry, David was doped up by a medical professional—and that's just anesthesia making him wacky. The unintentional hilarity, of course, is that he sounds exactly like every other person who has ever gotten way too stoned. "Is this gonna be forever?" We've all been there.
Greyson Chance (May 2010) Prepare yourself for Bieber 2.0. Turnaround on YouTube memes is a lot faster these days: as soon as Greyson Chance's "Paparazzi" cover blew up on the site, Ellen Degeneres snagged him as a guest on her show. Now he's got a record deal and personal guidance from Lady Gaga herself. Clearly, the latter is more exciting.