rFactor with the best mods is as good as anything. Really doesnt matter that the tracks/cars you get with it aren't that great. Bolt on the 1979 F1 mod and you've got one of the best F1 games around, or the PCC2007 mod and you've got a great Porsche GT3 game (IMO better than the Porsches in GTR/GTR2), or Meganes, Clios or Caterhams, whatever takes your fancy, plus there's so many quality tracks available. All the GTR2/GTL tracks have been converted, plus loads of others. Take a look at rfactorcentral.
Agree about RBR, best rally game ever, but the realism means it's quite difficult so it's not for arcade gamers.
TDU drives really weird, just nothing like real cars but then it's not a sim just a fun free roaming arcade game.