SAFD:
Since you specifically said to watch on a trip I would have to remove any of the movies that would make me cry (looking at you, Up!)
But seriously, this is asking like which child you love the most.
Brave (this is the only obvious choice for me)
And then it would come down to am I sharing this screen with my kiddos or husband
which means it could be Aladdin, Lion King, Tangled, Princess and the Frog, Encanto, Zootopia, Little Mermaid, Beauty and the Beast, Mulan, or Wreck it Ralph.