Little Shop of Horrors (1986 movie (I haven't seen the 1960 version) Space Channel 5 (Both one and two)
Grease, Les Mis, and Hairspray are ones that come to mind. I also really love the soundtrack for Newsies, but I haven't seen it. And Phantom of the Opera! How could I forget?
My all time favorite musical has to be Cats. I used to watch the 1998 production on dvd ever since I was super young and always wished to be part of the cast. The West End production will be coming to my country in January and I will be going to see this musical live for the very first time on my 21st birthday! So excited!
Hamilton, Be More Chill, Heathers, also more classics like Phantom of the Opera and Les Miserables and The Sound of Music, In the Heights, Newsies, Dear Evan Hansen, Grease, Mamma Mia (one that I got into more recently), Falsettos (though I still haven't listened to the entire production. It's a long musical)