I would have to say that F1 is the pinnacle of motor racing technology. The ammount of money spent on those cars is sickening.
Yeah, NASCAR maybe doesn't sound that interesting when you realize that it is mainly 43 cars literally going around in circles but when you throw 43 of some of the best drivers in the sport on to, say, a 1/2 mile track (like Martinsville) it gets pretty damn exciting (you wanna see passing? look no further). Not to mention the restrictor plate tracks like Daytona and Talladega where the lead changes anywhere from 30-40 times in 200 laps....but yet there is no passing? Tune in to the Pepsi 400 this Saturday night (If you can). You'll see plenty of passing. And, they have road races too! This past weekend they were at Infineon Raceway (what used to be Sears Point, I hate how they changed the name, damn corporate sponsorships), and they also go to Watkin's Glen in New York.
OK, but I honestly love and thoroughly enjoy ALL motor racing. From 1/4 mile drag racing, to champ car/indy car, sprints, go carts, superbike, rally....the list goes on and on. My Girlfriend hates weekends cuz all I do is switch around the channels looking for racing on the tube (unless, of course, there is a Red Sox game on!)