Years ago when this question was first posed to me, my choice was Thomas Jefferson and he has remained firmly ensconced at the top of my list for all of the many years since ... I can't think of any other individual whose contributions to this (or any other) country come anywhere near the magnitude as do Jefferson's ... one of the little known reasons I find him so fascinating is that he so delighted in hosting dinner parties of the very type outlined in the question ... so much so, in fact, that he invented the lazy susan and the dumb waiter for the express purpose of having food arrive in the dining room without it having to be borne by servants ... his lazy susan was an entire door with shelves that rotated and allowed him to take plates of food and serve his guests himself, then remove the dirty dishes and send them away ... similarly, his dumb waiter brought food up from a basement level where it had been prepared ...
He was an utterly brilliant man who could hold a learned conversation on any topic with any other individual ... and, although the question was posed in such a way as to pre-suppose that anyone selected for the dinner invite would join in a smoke, Jefferson was a tobacco farmer who was a lover of the leaf (in particular, the VA tobacco that I find so alluring) ...
IF, for some reason, Jefferson were somehow unavailable on the date of my dinner, Mark Twain would have been my second choice ... he too was a brilliant man of many accomplishments who would make an utterly fascinating guest for an evening ...
It's interesting that even in the limited number of responses to the question so far, some of the most common answers have been given ... in the years I've been asking this question of a great many people , the most frequent response is that they'd opt for a deceased parent or grandparent ... and a significant percentage say Jesus would be their choice ... a surprisingly (to me) frequent answer we've not seen given here is Elvis, someone I'd never even consider and cannot fathom why anyone else would either, given the many preferable alternatives.