whilst it's roundy roundy, I've always fancied both Indy and Daytona - there's something about the technicalities involved in making a highly tuned engine run flat out for hours on end, and I love the excitement of the finishes (seriously, you'd think they'd learn to make sure they come in for fuel at the right time, so that they didn't run out on the last lap!).
One day, I will do a complete year in the States, do Sebring, Petit, Indy, Daytona, and an NHRA drag meet - american racing might struggle with proper corners, but they do know how to put on a shock and awe event of this kind of scale!