The $50 admission seemed a bit steep; however, after having visited I understand why they charge that much - the place is a mini-theme park, though with more exhibits than rides. Multiple restaurants (not well-themed, but they try), outdoor and indoor attractions, IMAX movies, and even a ride. We managed to cram in everything we wanted to see in a day, though it involved gulping down lunch standing up in 5 minutes (the cafeteria on the main campus is terrible btw).
We toured the rocket garden, which includes an Apollo capsule you can lie in for a photo op, the Saturn center (including an Apollo launch control room simulation), the IMAX Hubble film, launch experience, the VAB tour (extra $$), and the launch pad tour (extra $$). Both tours were worth it, though they could have easily been combined into one tour - parceling the experiences into separate tours is just a blatant scheme to weasel more money out of tourists.
I'd definitely recommend doing at least 1 "special interest" tour, since you can't drive around and see all this stuff yourself. But which tour should you take if you only want to pay for 1? The VAB tour was 2 hours and spends more time rambling around the grounds with various views of the launch facilities than it does in the VAB. Considering the VAB is usually a giant empty building, I wouldn't think this particular tour is really worth the money... but when we were there Endeavor was being temporarily staged inside, and a few moments alone up close to the shuttle was more than worth the extra cost. Overall you see more on the VAB tour than the launch pad tour; however, the launch pad tour (which is new) takes you inside the launch pad secure area. You don't actually get inside the flame trench or atop the pad itself, but it's definitely a closer view than you're afforded from any other tourist location. Overall I'd recommend the VAB tour if either you want to see the panoramic views of the many launch pads or if there's anything being worked on inside the VAB; otherwise I'd have to recommend the launch pad tour just for the feeling you get being that close to an abandoned structure that once sent shuttles into space.
This review is the subjective opinion of a TravelPod member and not of TravelPod.com.