Perhaps the best car is a zen car. A car which allows you to NOT think about your car, to not second guess the goodness of your car.
Perhaps it must be electric or hybrid. Definitely not just a pure gasoline car.
At the moment, I think the most zen car is probably a maxed-out Telsa Model S (Plaid) — black on black. Why? It is a ‘sleeper’ — it is waaaaay faster than any other hyper car or sports car in production (acceleration is only 1.99 seconds from 0-60 — puts other cars to shame). And black on black is ideal, because it is the most long-term robust color scheme (black is boring, but typically black is always in style, long-term).
Or the other option: the hilarity of a ‘murdered out’ black on black on black Prius (Nightshade edition). A more affordable option.
Perhaps the most fun car (gasoline) might be a black on black Civic Type R. Manual transmission, and the highly great practicality of a hatchback design (fun car to drive, and to get groceries). Probably the best ‘bang for the buck’ and unique import Japanese sports car.