Isle of Man would be great to see. Along with Pikes Peak, it's about the only major race where fans can get really close to the action. Dangerously close: that waiver on the back of your ticket actually means something!
Racing has become extremely safe today and that's a good thing. In the past we lost too many great drivers (Clark, Senna, and Earnhardt) and fans (83 at LeMans in '55). But all the safety measures have made racing less enjoyable to watch in person. Speedways have so many layers of catch fencing that they resemble maximum security prisons, and with the cockpit enclosures in F1 and Indy you can barely tell there's a driver inside.
F6Dave, u r right, it has become much safer. So safe that the biggest risk is a high-side or getting run over. But going off track into a gravel pit or soft barriers are great improvements for safety. One of the best rides one can plan with your friends is go to a pro (or even regional) road race at one of the many tracks in the US where AMA races are held. I raced at NHIS, Daytona, and Mid-Ohio. Watched races at other tracks too, but I recommend a planned ride to go see a motorcycle race near those who ride. In addition to several races based on displacement, they also have vintage races, and team endurance races.