Family excluded and just a single person? That makes it hard, because honestly my favorite dinners are having friends over and we are all doing the prep work in the kitchen together, chatting, laughing, dancing and then spending the evening eating and talking and - there's probably drinking, too, and more laughing.
If I have to go for a single person it would be someone from history, way back, Leonardo da Vinci comes to mind. He was an amazing man of such diverse interests and knowledge that it is mind boggling. I probably wouldn't understand 90 % of what he would say over dinner, but despite that I am sure it would be a delightful time.
da Vinci would be a great choice I think; intelligent, knowledgeable and creative. Whether you were to understand most of what he said or not I feel there'd be a lot of value! I wonder what culinary delights you would serve or where you would go for dinner?