For Magic Kingdom, I think your best bet might be to go with the three Mountains (Splash, Thunder, and Space) in Magic Kingdom. Seven Dwarfs Mine Train is new and I haven't ridden it yet, but maybe that in place of one of them. I recommend FastPass+ for all three of those rides which might allow you a little extra time to do a few other thing while you're there too. You should try to hit Magic Kingdom as your second park for one day because they have one of the nicest fireworks shows.
For Epcot, I recommend Soarin', Mission Space, and Test Track. Again, you can Fastpass 2 out of the three of these (either Soarin' OR Test Track can be FastPassed, but not both). I'd do Epcot earlier in the day, maybe in conjunction with Magic Kingdom since it's a slower park. I'd also recommend having at least one meal at this park, since it's the best out of the parks for eating! : )
Next, for Hollywood Studios, I'd recommend The Tower of Terror, Rockin' Roller Coaster, and either Star Tours or Toy Story Midway Mania. Again, FastPass them. I'd do this park in the evening too because Fantasmic is a great show. Try to eat at 50's Prime Time Cafe if you can (they yell at you for using bad table manners and it's really fun to go there with teens)
In the same day as Hollywood Studios, do Animal Kingdom in the morning. Here I'd recommend Expedition Everest, Dinosaur, and Kilaminjaro Safaris.
Note: Especially if you're on a tight time constraint, be sure to go on Disney World's website, make an account, and reserve dining (at 180 dyas out) and FastPasses (60 days out if you're onsite and 30 days out if you're offsite). This will help you make sure you get to do everything you want. Trust me, a little planning goes a long way.
Have fun!
