NBC

1954–1959
On January 1, 1954, a xylophone and mallet was shown with a three tone "G E C" tone, as seen in the Video section. The keys refer to the General Electric Company (G, E, C).
 * Youtube: NBC ID

1956–1975
On May 22, 1956, NBC started using a logo for their color programming. The original peacock is a lucky find today. In 1962, they changed the logo. On a kaleidoscopic background, a majestic tune plays, as the NBC peacock fans its feathers and then turns into the logo from before.
 * Youtube: Original 1957 NBC Peacock
 * Youtube: 1960's NBC Peacock

1959-1975
The chimes were rendered obsolete by 1960 as a new logo, dubbed the "NBC snake", arrived. There are some variants of it but the most famous is the one where it draws itself.
 * Youtube: NBC Snake logo (1965-1975)

1976–1979
This short-lived abstract N logo was first unveiled on October 1975 and premiered on-air January 1, 1976. Nicknamed the "Trapezoid N".
 * Youtube: NBC ID
 * Youtube: NBC logo bumper from 1977

1979–1986
This is shown with or without the stylized "N"; although the version without the "N" was rarely seen after 1980. The network had, by this time, decided to take a new approach in its programming to introduce the slogan, "NBC - Proud As A Peacock!". Nicknamed the "Proud N".

1986–Present
A new logo, created by Chermayeff & Geismar, was finally launched on May 12, 1986. Chermayeff & Geismar are also responsible for the logos of PBS, Chase Manhattan Bank, Screen Gems Television, and others. This remains use as the on-screen bug.
 * Chermayeff &amp; Geismar

2011–2013
On May 2011, NBC altered and modified their logo slightly to feature bevels and gradients. Other aspects of the 2009 graphics package remained intact.

2013–present
On April 2013, NBC altered and modified their 3D logo.

To see more stuff from NBC go here: NBC/Others.