Depends on your group. Big headliners or Kiddie rides. I will do my list for both
With small kids-
MK- Peter Pan
AK- Safari
DHS- Toy Story
Epcot- Depends on a lot of factors, so I will say Soarin or nemo
With bigger kids/adults
MK- Splash, Thunder Mountain or SPace Moutain depending on preference and what you can get FP for later
Epcot- Soarin or test track
DHS- I'd do Rockin Roller Coaster first then go to Tower of Terror. I liked the Que in TOT
AK- Mt Everest