It honestly depends if he is really into Disney or not. I am also 19 but I LOVE Disney so I am willing to do any ride, restaurant or park.
However for many teenagers, I would say that RnR Coaster and Tower of Terror are a must at DHS. I also think that he would probably enjoy Toy Story Mania, it's a fun family ride but we also grew up with that movie so it could bring back memories! At magic kingdom I would say definitely Space Mountain and the Buzz Lightyear Ride. I also think that Monsters Inc Laugh Floor is a good show as well. Animal Kingdom the safari and Everest are a given! Epcot I think he would probably enjoy Test Track and Soarin and depending on what he likes he may enjoy seeing all the different countries!
