I'm an extremely rare to rare person. To me, medium rare is tolerable - beyond that, its a waste of a good steak. Unless we're talking about something sliced super thin like flank steak or london broil.
When I was a kid I'd eat raw hamburger, but these days, after the article I read in the New York Times about how hamburger is made, I keep to medium well. I'll only eat Bubba Burgers, or hamburger from our local grocery store where they make their own out of table scraps, not random vats of fat from goodness knows where.