I have quite a few...
Those corners after Dottinger Hohe on the Ring - you're closing at warp nine, the first one (Tiergarten?) gets the car unstable, and then you have to slam on the brakes for the second one (Hohchicein? Is that how you spell it?). You either brake too late and wreck, or brake to early and get hit/passed by everyone who isn't already ahead of you.
T1 on Daytona Road - I don't think I need to say anymore about this, do I?
Just about everything on TGTT -
First left hander: Where's the apex and how do I hit it?
Chicane between that and Chigago: Always go through here too conservatively
Chicago: Usually go in too fast and make a very, very late apex
Hammerhead: Very easy to overshoot
Second to last corner: The track goes from very wide to very narrow here, and it can fool you easily. Remeber all those celebrities that spin out/run through the grass? Yeah.
Last corner: Nearly always overshoot this one.
First chicane on Monza - I always get the braking point wrong on this one, adding huge amounts of time to my lap. And if I'm online in traffic, that's definitely some good times. NOT.
T1 at Fuji - VERY easy to overshoot this corner, braking point is impossible to find
The post above mine reminded me of Degner @ Suzuka - that corner hates me.
To be updated later.