The four worst aspects of the modern Romeo and Juliet are
1) The setting: It’s not even close to being the same as the play. It doesn’t have the same appeal it did in the play.
2) The Lines: Despite the language of the play remaining unchanged, notably with the characters still referring to their guns as "swords," the original play still changed dramatically on its journey to the big screen.
3) Rosealine’s Not appearing: Rosaline is a character that doesn't appear in the play and plays an important factor. She is Romeo's first love and the reason that he is distraught at the beginning of the story, as she does not love him back, having instead sworn a vow of chastity. Rosaline is the main reason that the Montague characters visit the Capulet's party, as she is meant to be there.
4) The Balcony Scene: The film decided to change the legendary scene, firstly by reducing the 190 lines to just 90 lines. Secondly, the setting changes from an orchard scene to a more modern and sexualized scene in a swimming pool.
I’m sorry I can’t think of any best parts. I wasn’t a fan of the movies