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!
I did go to Daytona several times, for the 500 and the 24h, the races I saw never let me down and were great to watch.
24h race, and the first 4 cars head into the pits together about 45 minutes before the checkered flag, never seen anything like that over here in Europe. The drafting in Nascar is also pretty awesome to look at, flat out and only inches between the cars, or even pushing the guy in front. Completely different compared to the racing we're used to, but sometimes great fun to watch.