Well, if you are thrill seekers, the only real thrills in MK will be the mountains (Space, Splash, Big Thunder) and 7 Dwarfs Mine Train. If you are early risers, get to the park before it opens so that you can get there as soon as they let you in and you can line up for 7 Dwarfs or Space Mountain. If you are staying at a Deluxe Property, you will get 30 minutes in Fantasyland and Tommorrowland before other guests. You can check out 7 Dwarfs and Space then. HOWEVER, those are super popular so one you can do in the early entry and then use Genie+ for the others. If you time things, Big Thunder or Splash can be done in Standby. It all depends on your style and if you are late night or early bird, etc.
Check out the Genie + thread.