If on the street your opponents happen to also be able to take good ukemi and limit their attacks to gedan tsuki and yokomen then Steven Seagal was most certainly promoting a street-effective type of Aikido in his movies. Oh, and we can't forget the ever-popular front snap kick to gedan tsuki provided by Matsuoka in half of his movies so he can do that nifty I'm 6'5 and you're 5'8 iriminage!
I love Seagal's older movies, but it looks like Aikido to me. They just throw in a few broken bones here and there and the ever popular arm snapping sound effects. If you watch any of his demos on youtube it looks like good, smooth Aikido. If you want brutal watch an Isoyama video. Sometimes he makes me wince. http://www.youtube.com/watch?v=B9PQCQV1krY