Didn't mean to pressure you guys...
I'll go through the game and see if I can come up with any suggestions. Off the top of my head, I don't think we've run Major Micros at all. Forza Specials, either. Some previously-run Divisions at lower-than-homologation requirements might work well, too; Vintage GT Racing at C500 (bust out those D-types and DBR-1s), Nostalgic Drag Racers at D400, etc. Probably a ton of those we could run that'd be "new" for most of us.
Track-wise, Rio Coast is a great track for lower PI cars that I don't think anyone but me ever drives on (it's one of my two damper tuning tracks). The other super-duper short Rio one (that isn't Mountain), too. We've barely touched VIR; metric ton of options there. Wish we had more Nurburgring variants; some of the shorter configurations of the GP circuit are pretty awesome for slower cars.
Just no Dubai. I
Kefka-hate Dubai. Worst track in any Forza ever, and that includes the original New York.