One of the most interactive Hall of Fame/Museums I've ever been to. That means a lot coming from someone who lives in DC!
I definitely recommend one of the combo packs if you plan on doing the simulator. One race isn't really enough to get the hang of it. We did the $33 combo with admittance, lunch, and unlimited simulator rides. The pulled pork sandwich wasn't bad for lunch, and when you figure a regular admission was already $20 it was a solid deal. The various quizzes and interactive games were also fun (and educational!).
We ended up spending four hours there between the exhibits and simulator- make sure you have at least 2-3 hours available!