Adelaide, Australia. It's my home town. It's the capital city of south australia. It's not very big by city standards (but big enough to host F1) and Le Mans GP, more like a very large country town, but big enough to have a good night out on the town, but given 1 hours drive, and your in the middle of the bush... Fantastic.
2nd on my list, Melbourne (they stole the F1 from us). But that's just for the motorbikes.