Prost has always been my hero, so definitely him. My other absolute no brainer choice would be Keke. That man has so many stories to tell.
Out from the current crop, it would be Vettel, hands down. He seems to be the most intelligent and thinking one. Also, he seems to be the most "old school one" in many ways. It has long been a pet peeve of mine that modern drivers have one-size-fits-all personalities, interests and hobbies.
Back in the old days, you had people like Reutemann, who was always interested in politics. You had Cevert or de Angelis, who were classically trained piano players. Jackie Stewart was an excellent skeet shooter (almost made it to the Olympics!), Hunt was into breeding budgerigars, Mansell is a trained aerospace engineer, etc. So many aspects, so many interesting stories, interests, hobbies, backgrounds.
But nowadays, the drivers' personalities are seemingly made from the same mould. Note that this doesn't mean they are exactly the same. But how many would say that they are interested in being classically trained as a pianist? How many are avid readers of literature? How many pursue interests like breeding birds or spending time studying engineering?
Ask any of them what their interests are, and you basically have shallow, superficial and very similar answers. Hanging out at parties (surprising!), spending time on social media (wow, original - every teenager does that). They like scuba diving (which rich person doesn't?), they like sushi (how unique), and they don't really seem to be interested or knowledgeable in anything that requires time, attention or devotion. I'm not sure what the reason for this is, but it might be a generation thing. It's not that they need to be college-educated intellectuals. But at least some variety in their interests or hobbies or pursuits or pastime activities would be nice to see.
Anyway, the point is: Vettel seems to be the only one who is totally different. He is not active on social media; he doesn't have an entourage or a Twitch account; he likes reading about F1 history, he is interested in seemingly unusual things for an F1 driver like going to the theatre to watch a Little Britain show. I can't name any other driver who has good general knowledge about F1 history or who would go to the theatre in their free time.