Wrong Earnhardt if you're talking all-time.
Although you could certainly argue little E's the most popular driver now (even considering a relative lack of success since he's moved to Hendrick).
All that being said, I don't see a huge overlap between gaming enthusiasts and NASCAR fans.
That\s why I added "famous" to "best" since I've heard many an argument against Jr.
Do people that watch NASCAR play videogames on consoles?
Of course they do but I agree, they wouldn't be enthusiasts. They are the casual fan who doesnt read sites like game trailers or Neogaf but also are who buys Big Game Hunter every year.
(Somebody has to be buying those games and I think it's safe to say, nobody who read sites like neogaf, ign etc are buying those game)