...huh. That's an exercise I also do. (Or the variant of "you can yank someone from the past into the present, at the time of their purported 'death'. They get as long or as short a time in the modern day as they want, but when they're done they return to the moment of their death.")

The one that always jumps to mind for me is Abe Lincoln - more to tell him about history after his death than anything else, though I'd certainly enjoy the chance for conversation - he died at kind of a crux-point, and from what I've read of the man I think he'd be relieved to learn how things turned out in the long run (though certainly grieved by some of the short-term events after his death).

For the pulling-forward variant, the one that usually jumps to my mind is Benjamin Franklin.