I cannot comment on the STCC tracks as I don't have that (bought the RACE ON expansion pack). I voted for Imola 08 and Road America. Road America is definitely my new favorite track. Imola 08 isn't as "pretty" as the 07 one, but I for one like the fact that they took out that stupid chicane after the pit entrance, although, like Andreas said, they could've made it a bit more interesting than just flat out.
I used to like Brands Hatch until it got soured for me by all the people claiming to run 1:14s and such, and then you watch them and they always go completely off after Paddock Bend Curve, just to keep up speed, which, IRL, would get them DQ'd.
I know it's just me, but I just can't make myself like Laguna Seca. Maybe because I had such High hopes and expectations, I feel let down. It just doesn't inspire me to drive it. I find it boring, yet all my friends love it. i almost hate to drive it now.
Same thing with Nordschleife: just a drive in the country to me. I actually enjoy the DL track Sachsenring67 more.
On a final note (again, I know, it's just me), I really don't find Simbin's tracks all that fun. I tend to run many more DL tracks from here at RD or from NoGrip so I guess my votes should be taken with many grains of salt, LOL.