Viral YouTube videos of 2012

Gangnam Style
The video became YouTube's most-watched video of all time, registering more than 803 million views to overtake Baby by Canadian heartthrob Justin Bieber.
http://youtu.be/9bZkp7q19f0

Barack Obama vs. Mitt Romney Epic Rap Battle
Epic Rap Battles of History is a YouTube video series created by Peter Shukoff (aka Nice Peter) and Lloyd Ahlquist (aka EpicLLOYD). The series pits famous historical and pop culture figures, either fictional or otherwise, against one another in a rap battle format.
http://youtu.be/dX_1B0w7Hzc

Call Me Maybe
Call Me Maybe is a song recorded by Canadian singer-songwriter Carly Rae Jepsen for her EP Curiosity (2012) and appearing on her international debut album, Kiss.
http://youtu.be/fWNaR-rxAic

Britains Got Talent Opera Duo Johnathan & Charlotte
Jonathan and Charlotte, are an English classical crossover duo from Essex. They finished as runners-up in the sixth series of Britain's Got Talent in 2012.
http://youtu.be/ZsNlcr4frs4

Dumb Ways To Die
Dumb Ways to Die is a public service announcement campaign by Metro Trains in Melbourne, Australia to promote rail safety. The campaign went viral through sharing and social media.
http://youtu.be/IJNR2EpS0jw

Kony 2012
Kony 2012 is a short film created by Invisible Children, Inc., authors of Invisible Children, and released on March 5, 2012.  The film's purpose is to promote the charity's "Stop Kony" movement to make Ugandan cult and militia leader, indicted war criminal and International Criminal Court fugitive Joseph Kony globally known in order to have him arrested by the end of 2012, the time when the campaign expires.
http://youtu.be/Y4MnpzG5Sqc

A Dramatic Surprise on a Quiet Square
A big red push button on a quiet square in a small town in Belgium with a sign "Push to add drama". See what happens next.
http://youtu.be/316AzLYfAzw

Somebody That I Used to Know
Somebody That I Used to Know is a song written and recorded by Belgian-Australian singe-songwriter Gotye, featuring New Zealand singer/guitarist Kimbra.
http://youtu.be/d9NF2edxy-M

Issac's Live Lip-Dub Proposal
The Portland, Ore. actor asked girlfriend Amy Frankel to marry him using a pair of videocameras, a pair of headphones, a Honda CRV, a Bruno Mars ballad and 60 exuberantly shameless friends and relatives (hey, this is Portland). A video of the event, titled "Isaac's live lip-dub proposal" went viral  and has racked up some 5 million views on YouTube.
http://youtu.be/5_v7QrIW0zY

Felix Baumgartner World Record Free-fall
Felix Baumgartner is an Austrian skydiver, daredevil and BASE jumper. He set the world record for skydiving an estimated 39 kilometres (24 mi), reaching an estimated speed of 1,342 kilometres per hour (834 mph), or Mach 1.24, on 14 October 2012 and became the first person to break the sound barrier without vehicular power on his descent.
http://youtu.be/dOoHArAzdug