I love the concept of this video, it can be applied to many different aspect of architecture, including "women in architecture", "African American Architects", and maybe.....The ABC's of Hip Hop Architecture. Its a very catchy video. Check out the credits and official description below. I disagree that these are the most "important" architects, but I will say there are some of the most famous architects. Important and famous are very different.

"This work is an alphabetical list of the most important architects with their best known building. A lot of them have been left out with grief because we only need one for each letter and we done an effort to have different nationalities. If you love architecture, for more stuff you can follow us in ombuarchitecture.tumblr.com"

Concept and Animation: Andrea Stinga, Federico Gonzalez
Art Direction: Federico Gonzalez
Music: The Butterfly from Eugene C.Rose and George Ruble, (Creative Commons)
you can download it here: vimeo.com/musicstore/track/10358