YouTube

2005–2011
The logo consists of a black "You" and a red rounded rectangle with the word "Tube" in it. It can also contain the "Broadcast Yourself" tagline underneath. It was originally scheduled to be released in 2003, but was delayed until 2005. As of 2011, this is now being used as a secondary logo.

2011–2013
This modification of the YouTube logo was introduced in July 2011 as a part of the Cosmic Panda experiment. It officially became the new logo a few months later. With the introduction of the entirely new layout on December 6, 2012, the slogan "Broadcast Yourself" was retired.

2014–present
Around December 2013, the red was made slightly lighter in color.

Website History
This is a look at YouTube over the years.

Special Logos
Like Google or Orkut, YouTube changes their default logo to a stylized one with relevance to a certain date on various days throughout the year. These special logos can be found here.