This movie has one of the best opening scenes out of all the Marvel movies. What makes it so good? It's packed full of humor, great music, and a battle against a massive creature. Those details pale in comparison to what really makes this scene rock: baby Groot. After Groot sacrificed himself in 'Guardians of the Galaxy,' Rocket Raccoon used a branch to make a new Groot. Baby Groot is the best version of Groot, even if he's a troublemaker.
Ego, the bad guy of the film, is an interesting bad guy too, because for a majority of the film you have no idea. That's what makes this movie a lot more interesting than some other Marvel films. A good guy can only be as good as his villain. In this case, Starlord faces his own father. That's powerful stuff, man.