I would have to disagree that Seagal Sensei is the only rep. for Aikido in the film world. I would agree he is the most recognized. Another example would be Toshishiro Obata (who was an Uchi-deshi of Gozo Shioda). He appeared in such "blockbusters" as Showdown in Little Tokyo with Brandon Lee and Dolph Lundgren.
Also, I agree that you should train with Seagal Sensei to get a feel for the type of person he is. I have had the honor of training with him a few times. I found him to be an exeptional instructor and fun to train with. He was also a pretty personable guy