Meme: Ponies
Origin: TheTXI
Cultural Height: April 1st, 2009
Background: The pony meme began without fan fare early in TheTXI's time as a member of StackOverflow. It's first recorded usages can be traced back to long running comment threads and arguments on both StackOverflow and UserVoice. The comment "I like ponies" would be randomly interjected and would inevitably lead to the thread getting completely derailed.
Before long it became evident that TheTXI was not the only SOpedian who found ponies to be the most wonderfullest things ever. It's popularity grew to the point where even Jeff Atwood and the SO Dev Team implemented the Cornify button on all questions and answers on April Fool's Day 2009. From there the popularity of ponies (and their magical weaponized form the unicorn) grew exponentially.
Related: http://www.ponyoverflow.com