I can't comment on them as I've never seen them live, but Gilles from what I've watched/read/heard is the most talented driver ever. Extraordinary.
I doubt there have been many better than Alain Prost, not spectular, but very consistent.
Prost was a superb driver and utterly deserving of his title as "le professeur". He was never a spectacular or thrilling driver like Villeneuve or Senna but he was the ultimate grinder-out of results. Underrated because he wasn't stylish, but absolutely worthy of a position high in the all time top ten.