I think the person responsible for indoor plumbing would be cool to hang out with.
Oh, and definitely Pants Anderson, the inventor of pants. You know he would have some kick-ass stories to tell.
And maybe the person who came up with the gum eraser just so I could say "Thanks a bundle".
Last but but not least, The Beek. I know, I have met and hung out with him, but that was years ago, which means I never got to say "Thank you" for creating the single moment in television history.