Moreso than just, "listen," things are always better over a meal, so it would be 4 people to have to dinner. I would probably have 3 or 4 baseball players, but I'll put one from each sport of my favourite sports.
1. Eric Hinske; have met him 3 times and he is my idol/favourite baseball player ever. While I never struck out as much as he did, I modeled my entire game after he did. Always hustled (save for a few times in '04/'05), absolutely solid fundamentally and similar in build to myself, would love to enjoy a meal with him. Norwegian background as well, have never even spoken to someone else of that background, let alone meet one so that would be cool.
2. Karl Wendlinger; my 3rd favourite driver ever (after Prost and Schumacher), I would pick him for the sole fact that he raced WITH the giants of the late 80s/90s and was in the Mercedes academy with Schumacher. Austrian background puts him as another I've not met and they are on the border with Italy, so there would be a lot to talk about.
3. Whitworth; No-brainer. A wonderful human being (from what we can all see), I don't need to explain.
4. Jonah Lomu; he may have passed away, but definitely would be the person from the rugby world to invite. Played at the top, for the best team/nation ever and was just an absolute monster. And a NZer!
Honourable mention: Vinnie Jones; not a soccer fan at all, but absolutely love him as an actor and since he played in the CL, he counts!
If it were 4 baseball players:
1. Hinske
2. Andres Galarraga
3. Brian Giles
4. Roy Halladay