Road America or Road Atlanta? I'd love to go to both. I've been to AMA a few times at VIR, as you know its great for getting up close and personal with the riders and seeing the pits, but Moto GP just has a whole different feel, especially when you step into a massive venue like IMS or Circuit de Catalunya. You'll get major goose bumps when you first hear one of the mechanics fire up one of the bikes and start blipping the throttle in the garage. I'm really happy they are going to be bringing the 125's and 250's too, thats really important to the whole GP experience.
But yea seeing Moto GP in Spain or Italy is something I'd recommend anyone do once, if not many times, the people are just fanatical about the racing and the entire thing is just a huge great experience if your into racing, or hell even if your not.