In second place on YouTube’s annual Rewind list is Key of Awesome’s parody of Ke$ha’s “Tik Tok,” with 51 million views since being released in February. (The original music video by Ke$ha herself has only 34 million views on YouTube.)

And third is sixth-grader Greyson Chance’s school performance of Lady Gaga’s “Paparazzi,” which blew up online and scored him a record deal with Ellen DeGeneres. It’s been seen 34 million times since April.

Both the Gregory Brothers and Key of Awesome are affiliated with independent (though closely aligned with YouTube) video shop Next New Networks. And it’s notable that every one of the top three videos is musical–an original, a parody and a cover song–with two of them taking inspiration from current songs by pop stars.

Also on the 2010 most-watched Top 10: YouTube star Annoying Orange, advertising phenomenon the Old Spice guy, the Double Rainbow guy, an OK Go music video (the band left its label deal after a YouTube embedding rights spat), the “Twilight: Eclipse” trailer, a Jimmy Kimmel short involving Justin Bieber and a stunt-driving video by Ken Block.

YouTube split out major label music videos, as their viewing numbers are in a different stratosphere. Plus, the top-watched music videos list is more boring, with Bieber, Shakira, Eminem and Lady Gaga accounting for all 10 spots (and Bieber, who was discovered through YouTube, taking four of the top 10). Bieber’s video for his song “Baby,” which took the top spot, has been seen more than 408 million times since February.

Aside from videos, YouTube also released some additional stats, including its most-searched-for terms by month. YouTube has been measured as the top U.S. search engine after Google itself.

January – Haiti
February – Luge
March – eclipse trailer
April – iPad
May – Eminem Not Afraid
June – shakira waka waka
July – double rainbow
August – bed intruder
September – halo reach
October – whip my hair
November – firework

And lastly, YouTube also launched today a site aimed at the media called YouTube Trends, which explains the most viral content on the site at any one time.

In any case, here’s “White Knuckles,” the newest one, which has yet to actually go viral. If you like dogs and/or Target ads, you’ll definitely like this one (Bob Lefsetz likes the song better than the clip):

Bonus video! Another canine clip, featuring the awesome Jane “Sue Sylvester” Lynch:

*To be fair, the band would say it chose to leave EMI Music because it could do better on its own, and that’s not an unreasonable argument.

My colleagues are lapping the last one up, with good reason: The OK Go are fun to write about, because they make cool videos and because lead singer Damian Kulash is very quotable when he talks about the state of the music business and his band’s relationship with EMI.

For instance, here’s a stinging part of his exit interview with New York Magazine today:

Q: What other problems were you having with EMI?
A: ?The issue is that they just don’t have any money. The reason a band signs with a label is because they can provide start-up capital, and their business model has sort of collapsed. There was lots of little bones of contention, like when there were chances for us to promote things and they just didn’t have the money to do so. It was a lot easier to be generating the budget ourselves or through corporate partners.

EMI has issued a boilerplate quote wishing the band success–it’s going to create its own label–and leaving it at that.

And EMI does have real money problems. In part because everyone who sells music right now has money problems and in part because private equity fund Terra Firma paid too much and took on too much debt when it bought the label three years ago.

But here’s the thing. If EMI’s executives allowed themselves to speak candidly, they would likely point out that while the OK Go made great videos, it didn’t seem to make music that many people wanted to buy.

Soundscan says the band has sold all of 500,000 albums in the U.S., both in physical and digital form, in its three-album tenure at EMI. That’s 488,608, to be exact. Plus another 25,000 single tracks.

That’s not awful. But it’s not the kind of sales that would inspire a big label to spend big money promoting an act. Even when the industry’s business model was still intact.

But the band really does make nice videos that people like watching on Google’s (GOOG) YouTube. If it can figure out how to turn these into dollars, it’s all set.

OK Go–This Too Shall Pass from OK Go on Vimeo.

What gives? It’s sort of simple: The band would prefer that you watch the video via Google’s (GOOG) YouTube, but EMI won’t let Web users like me embed the YouTube version of the clip.

The band explains why this is so here, but it’s a story we’ve heard before–in a nutshell, it’s harder to sell ads against embedded videos.

That’s supposedly going to get better with Vevo, the “Hulu for music videos” joint venture that EMI is licensing its stuff to, so perhaps this kind of thing won’t be necessary in the future.

(That said, the band’s account is well worth reading, as it is a clear and even-handed assessment of the music industry’s attempt to wrestle with Web-era economics. Excerpt: “We’ve got this ridiculous situation where the machinery of the old system is frantically trying to contort and reshape and rewire itself to run without actually selling music. It’s like a car trying to figure out how to run without gas, or a fish trying to learn to breath air.”)

Meanwhile, the Vimeo situation is a bit confusing: EMI is suing the site because it encourages users to upload “lip dubs”–what you and I would call “music videos”–that use copyrighted songs without authorization. In this case, OK Go is the entity uploading the songs/videos, so I suppose that makes the legal situation more palatable (note the big copyright notice at the end). But I’m still not sure how or why the licensing/advertising issues that put the kibosh on the YouTube video don’t come into play here.

In any event, here’s the song, followed by a YouTube version of the one that made the band sorta famous:

OK Go – This Too Shall Pass from OK Go on Vimeo.

That would be, of course, Yahoo’s (YHOO) Jerry Yang, Microsoft’s (MSFT) Bill Gates and Steve Ballmer and corporate raider Carl Icahn.

Here’s the mashup video, with the original OK Go one–which I never get sick of watching–below it: