I was actually at KSC yesterday, so a timely question.
The tours have changed significantly over the past 12 months, as the shuttle program wound up and they moved to the SLS (Space Launch System). Personally, I wouldn't go with an organised tour to/from the center. I hired a car (around $250 for an entire week for an SUV; car hire here is cheap). The center is 60-90 minute drive each way, depending on traffic (and $4.50 in tolls to/from the Kissimmee area). Parking is $10 (yup, they gouge you for that too, they have learned from low cost carriers!).
Check out
https://www.kennedyspacecenter.com/tours.aspx for tours you can just purchase at entrance. I wanted to to the up-close tour as well, but my friends had no interest.
December 4 sees the first trial of the new rocket for this, and there's a real buzz amongst the staff there as a result.
I did the general entry and launch centre tour ($50+25 for the extra tour).
We arrived around 10am, and left at 6pm, and were never bored (in fact, we could have done a lot more but we just didn't have time).
There are 2 x IMAX shows, each of around 40 minutes (we didn't get time to do this).
There's a general bus tour that'll take you out towards Launchpad 39B (39A is where all manned space flight was from, and the last STS was launched from, but that is now leased to Elon Musk for the next 20 years, and that's having the STS infrastructure dismantled from it by his group, Space X). They drop you off at the Apollo Center where there's an Saturn V rocket mounted from the ceiling, a heap of memorabilia including a space rock you can touch and another theatre (didn't get time to see that but it was a 15 minute show). There are no outside spots for photos on this general tour. It's around 90 minutes for that, including the bus trip to/from the Apollo center.
The LCC tour (Launch Control Center) was meant to last around 90 minutes but ended up being around 2 1/2 hours. The tour guide was incredibly knowledgable. It's very clear that the tour guides love their job. They were all egging the visitors on for questions, and were keen to educate in an informative an interesting way. Well worth the money IMHO.
One thing to note, i'd probably not do the generic bus tour and the LCC. The LCC actually takes you a little bit futher past Launchpad 39B than the generic, and also to a stop you can get out and take some great photos of the launchpads. It then drops you off at the Apollo Center as well, so it's a bit of an overlap (in fact, you miss nothing if you don't do the generic and just do the LCC).
Back at the main visitors center, there's Atlantis, mounted very dramatically like it was flying in space (on a 45º of so angle, with the doors open and control arms out). There's a shuttle launch simulator ride which is kinda neat (and free) takes around 15-20 minutes, also at the Atlantis center. Lots of simulators there too, and some other cool stuff. I believe the queues are massive when busy, as the infrastructure is definitely in place for large queues.
Do not bother with the paid audio guides. I came to the conclusion it was a non-english speaking tax. The guides were so excellent, and the roaming staff were all brilliant and keen to chat about anything related to the programs.
Since January, there's no tours of the VAB (Vehicle Assembly Building) and other programs have been axed. The LCC is fairly new, and you get to go into the launch room where the last 21 STS were launched from. Interesting to note, these rooms only took the launch up to the first 8 seconds, then it was handed to Houston (basically once it clears the tower, it's out of their hands).
I wouldn't bother with the 'lunch with an astronaut' unless you're a space nut. They are genuine astronauts, but it's not likely to be anyone famous. The one yesterday was a lady, but I can't recall her name (I certainly did not recognise it).
There's an 'angry birds' thing which I didn't bother going in to.
I was last there 20 years ago as a kid, and I'm 100% glad I went back. Was truly a highlight of any trip to the USA i've had.
Also, be sure to hit up the factory outlet malls here. Never short of a bargain or three (and call by the visitors center with a voucher you can get off websites for a discount coupon book to make it even better).
Oh and try to go mid-week. There were almost zero children, and it was not busy. We also had amazing non-typical FL weather (around 25º and very low humidity).