Hmmm, perhaps Muhammad Ali. There's a man who was one of the all time greats at his sport and experienced the best and the worst of people at all levels - close associates, business partners, fans, government...
Ken Dryden was my favourite athlete as a kid but now that he's both lawyer and a politician he might be too boring to share a beer with. He's a highly intelligent, thoughtful, and articulate man with a good perspective about how and why sport is relevant but not the most important thing in life.
In cycling, I have no idea. I find that this sport as much or more than most others introduces fans only to the elite athletes, who may well not be the most interesting or impressive people in the peloton.