The Buffalo version is the best. It is very simple yet similtaniously very profound. We all know how many different meanings there are to the song, but one of the most common is the 'brotherhood of man' theme, we are all one in this world, but we are not the same. The herds of buffalo running throughout the video, they all look exactly the same on the outside. The buffalo are a metaphor for humans, except the outside of the buffalo is the inside of us, the humans. We are all the same on the inside, and no matter how different we are on the outside, on the inside, we are a herd of buffalo running through the field of life.
I also love the Berlin video, not for the drag or the trabants, but for the scenes of the band in almost black and white playing in a circle. In fact, if that were the whole video instead of the drag, it might be my favorite of the three. But alas, it isn't, and so the Buffalo is my favorite.