Play the original Pac-Man for free.
Of course the most obvious way to celebrate is to play the original game. How? Chances are your old Famicom or Atari game console is broken, displaced and long forgotten, along with the Pac-man cartridge. That's where the Internet steps in, with various online versions of it offers (even for free).
Play Pac-Man clones, like Google's.
While most clones were developed to profit from Pac-Man's fame, Google did it as a tribute. For two days Google changed its homepage logo to a playable version of the game. While this first fully interactive special logo is not on main display anymore, you can check it out here. As a hidden bonus, you can play Ms. Pac-Man as well with a fellow player by clicking the Insert Coin twice.
|Feeling lucky? Insert a coin.|
Most loyal fans of Pac-Man simply can't wait to express their love for the game. As such, they create tributes such as videos. Here's one by Annoying Orange: