Ah, I've been searching for this one! And let me know if there are any other related threads!
I just enjoyed some local twisty roads with long, sweeping bends and got to thinking about this topic. All the new tracks are very technical (the word 'sterilized' is often used), and they present a certain challenge. But I wish instead they just updated the safety standards on the classics because their corners challenge the size of your bollocks, not just your brake timing or steering angle!
Plus it makes for great racing. In particular, I was thinking of the old Osterreichring. Check it out:http://youtube.com/watch?v=Pr5HG1J845Y
A quote from Wiki: "It is also known that four-times World Champion Alain Prost often said that all tracks can be changed but that the Österreichring should remain unchanged, just adding run-off areas would be fine"
As others pointed out, these old tracks and their surroundings are so full of character which enhances so many things over a grand prix weekend including the excitement. My F1 favorites, past and present: Spa, Suzuka, Osterreichring, Brands Hatch, old Kyalami, Monza, Interlagos, Dijon, old Hockenheim, Zandvoort, and of course the Green Hell.
I could go on and on about all this but I'll spare you all!