Let's Welcome the Internet Phenomena

Today, many of these internet phenomena are also spread via popular, user-based or social networking Web sites, including (but not limited to) 4chan, Reddit, Facebook, Fark, Flickr, Myspace, Slashdot, Something Awful, or YouTube. Search engines, such as Google, Yahoo, or Bing may also amplify the propagation of these phenomena.

Being specific here are some list of internet phenomena by its categories;

ANIMATION

• Dancing baby – A 3D-rendered dancing baby that first appeared in 1996 by the creators of Character Studio for 3D Studio MAX, and became something of a late 1990s cultural icon in part due to its exposure on world wide commercials, editorials about Character Studio, and the popular television series Ally McBeal
• Happy Tree Friends – A series of flash cartoons featuring cute cartoon animals experiencing violent and gruesome accidents.  
• Weebl and Bob (UK: Wobble and Bob) - A series of flash cartoons created by Jonti Picking featuring two egg-shaped characters that like pie and speak in a virtually incoherent manner.  

ADVERTISING

• Cooks Source infringement controversy — advertising-supported publication's dismissive response to copyright infringement complaint causes online backlash.
• FreeCreditReport.com — series of TV commercials that were posted on the Internet; many spoofs of the commercials were made and posted on YouTube.
• Lowermybills.com — Banner ads from this mortgage company feature endless loops of cowboys, women, aliens, and office workers dancing.
• Embrace Life — a public service announcement for seatbelt advocacy made for a local area of the UK which achieved a million hits on its first two weeks on YouTube in 2010.
• Shake Weight - Infomercial clips of the modified dumbbell have gone viral as a result of the product's comically sexual suggestive nature.
• The Man Your Man Could Smell Like — A television commercial starring Isaiah Mustafa reciting a quick, deadpan monologue while shirtless about how "anything is possible" if men use Old Spice. It eventually led to a popular viral marketing campaign which had Mustafa responding to various Internet comments via short YouTube videos on Old Spice's YouTube channel.

EMAIL

•  Bill Gates E-mail Beta Test – An e-mail chain-letter that first appeared in 1997 and was still circulating as recently as 2007. The message claims that America Online and Microsoft are conducting a beta test and for each person you forward the e-mail to, you will receive a payment from Bill Gates of more than $200. Realistic contact information for a lawyer appears in the message.
• Mouse Ball Replacement Memo – A memorandum circulated to IBM field service technicians detailing the proper procedures for replacing mouse balls, yet filled with a number of sexual innuendos. The memo actually was written by someone at IBM and distributed to technicians, but it was distributed as a corporate in-joke, and not as an actual policy or procedure. On the Internet, the memo can be traced as far back as 1989
• Goodtimes virus – An infamous, fraudulent virus warning that first appeared in 1994. The e-mail claimed that an e-mail virus with the subject line "Good Times" was spreading, which would "send your CPU into an nth-complexity infinite binary loop", among other dire predictions.
• ILOVEYOU, also known as LoveLetter, is a computer worm that successfully attacked tens of millions of Windows computers in 2000 when it was sent as an attachment to an email message with the text "ILOVEYOU" in the subject line. The worm arrived in email inboxes on and after May 4, 2000 with the simple subject of "ILOVEYOU" and an attachment "LOVE-LETTER-FOR-YOU.TXT.vbs". The final 'vbs' extension was hidden by default, leading unsuspecting users to think it was a mere text file. Upon opening the attachment, the worm sent a copy of itself to everyone in the Windows Address Book and with the user's sender address. It also made a number of malicious changes to the user's system.

TRADING

• Freecycling – The exchange of unwanted goods via the Internet.