Everyone is happy and gets to be with the one they love
All of the Athenians end up married to the person they're in love with (Theseus and Hippolyta, Lysander and Hermia, Demetrius and Helena), even though some of that is due to Puck's intervention.
The conflict between Oberon and Titania is resolved and they end up happy together.
The mechanicals get Bottom back and are all happy to have each other and to have gotten to perform their play for the wedding reception.