I agree that there are a lot of challenging corners out there. To me, there is a difference between Challenging, and Dangerous. The corners that Becky talks about are dangerous in that in order to go fast over them, you have to take a line that would never be used in the real world and if you don't hit them just perfect, you wreck.
I prefer corners that are challenging to get right and if you don't, you lose time and possibly wreck, but can also be taken reasonably fast if you don't get it just perfect.
Aston National turn 1 to me is a cool corner. It is tough to get it perfect. You always feel you could get just a bit more out of that corner. The last turn on WE1 is very similar. I like both of these corners in both directions because of that.
I don't like some of the chicanes, like FE Club R on the back ~straight and the chicane on KY3 coming off the oval section. I consider these dangerous corners. People take unreasonable lines over those curbs that will work 7 times out of 10, but will wreck you the rest of the time. In order to be fast on those tracks, you have to drive that way (lines that would never be used in real life). I prefer chicanes like the revised Blackwood chicane, possibly the chicane on the back-side of WE1 and some others where you take some curb to be fast but not a lot, and requires skill and throttle control instead of random chance to be fast.