Talking Typography

Letters, numbers and other typographical symbols that talk.

Fan Works

 * Fan art and Doujinshi for The Idolmaster frequently portray the "Producer" -- i.e., the player -- as a human with a capital "P" for a head.

Live-Action TV

 * Sesame Street loved these as well.

Toys

 * Part of the wave of 1980s Transformers knockoffs were a line of letters and numbers that turn into robots. There may not have been a back-story.

Video Games

 * Most of the characters in Three in Three, starting with the protagonist, Ms. 3.
 * The Unown from Pokémon resemble the 26 letters of the Latin alphabet as well as a question mark and an exclamation point, but the only thing they can actually say are their own names.

Web Animation

 * Charlie the Unicorn: Brought to you by the incredible singing Letter Y.
 * Pixar Logo Gone Horribly Wrong!

Web Comics

 * Adventures in ASCII.
 * The Perry Bible Fellowship has a typically acerbic twist on this idea.
 * Penny Arcade has a talking period, correcting trolls and addressing fan outrage. And this.

Western Animation

 * The children's show Word World has animals that are made of CG letters.
 * ReBoot featured numerous numerals throughout Mainframe, most prominently 7, 8 and 9.