In terms of driving pleasure, you have to include Suzuka and Spa. Because it’s in so many of them, I always think a great test of a racing game is how much fun Suzuka is to drive. Monaco is a great unique challenge and some Tikedromes are remarkably good fun. Speang in particular has a nice flow to it.
For racing, some simpler tracks like Albert Park and Montreal deliver more often than not, as do Spa and most of the Tilkedromes. Suzuka and Monaco… not so much.
In terms of non-F1 tracks, you have to look at Mugello, Laguna Seca, Imola, Brands Hatch and maybe somewhere like Road America. I also like the Barber Motorsports Park from IndyCar.