I'd love to be able to do a muscle-up. Stuff like running a marathon and 100 push-ups wouldn't interest me as much, because it's not stuff you can do to shut someone up instantly. 50 pullups sounds like a ridiculous target to me, especially if you're talking about proper pullups, where you go all the way down to straight arms and you've got your palms facing away from you. I'd be happy with 15, and then I'd start adding weight rather than trying to do more.
When he was in jail, something like 2000 sit ups, ive heard for Mike Tyson.. Ron Lyle used to do 800-1000 push ups... In total volume remember, them numbers would not be straight off...