I've always thought the Steven Seagal is the real deal. I'm the first to admit that his movies have gotten worse and worse over the years and yes, he's gained weight and aged. It's easy to forget that 'Above the Law' came out in 1988.
I encourage people to research Seagal. Like him or hate him, I think you'll find that a whole bunch of people agree that he is an incredibly talented martial artist.
This has been on the Internet and YouTube for a while now, but check out this clip of Seagal training Anderson Silva from the UFC.