Anyone from the past or present, someone you think you'd learn from or be driven by - or just plain enjoy the company of. Sure it's a not really meant to be a serious question but hey!
I think it would be an experience to train with, or rather be told what to do by, Vince Gironda in his gym (pic)
If i didnt hurl after doing sets of front squats with 30 seconds rest between them then the lovely shake of half and half stirred in with a dozen raw eggs would give me another opportunity soon after! (and he'd throw me out of the gym for messing up his floor!)
I'd learn a lot from him anyway, very intense man with lots of experience.