The move Amadeus, while not accurate historically and biographically, can be a nice introduction to Mozart’s music.
The Magic Flute is considered his most accessible work and is a lot of fun to listen to for a newbie. His Requiem, while considered one of his finest works, is not as accessible, but the introduction you get to it in the movie is good taste of it for the casual listener.
I highly recommend the chamber music playing in the beginning of the film where Salieri first hears Mozart’s music. Mozart adored the clarinet and wrote some of his finest music for the instrument and the piece they use in the movie is an excellent example. The Salieri character even parses it for the viewer, talking about the soaring clarinet line over the clear, measured and supportive ensemble instruments.
Everyone knows Eine Kleine Nachtmusick, and it’s a fine piece, but there are so many better ones to listen to if you just dig a litte. I highly recommend his clarinet quintet, which is a personal favorite. Again, anything Mozart wrote featuring the clarient is going to be among his better work.
Things are very important about Mozart’s life - he was a child prodigy and he was writing incredibly sophisticated music by the age of 5 or 6, music that just kept getting better as he got older. He was apolitical in a very political time, and while his music brought him accolades, his inability to play the game politically left him financially strapped. Sadly, he died very young at the age of 34, I believe. Considering the incredible quality of the music he composed, one has to wonder how much we missed by losing him so young.