Both were win at all cost drivers, but Senna takes it for me as he had a bit more flair. I met Shumi at the race of champions and he was a dry cunt.

There were a lot less driver aids back then and nowhere near the same aerodynamics, I think this video is a good example of how much more driver input was required to keep the car on the road in comparison to today's cars.

http://www.youtube.com/watch?v=GTJZTc1U1tM