They certainly weren't the only interesting ones (see this story about Gesualdo (I'm not sure the data in the last paragraph is all accurate), a Renaissance composer who used in his music what I've seen described as Wagnerian chromaticisms, and murdered his wife and her lover when he caught them).
They were interesting in the movie and play it was based on, "Amadeus" (F. Murray was WONDERFUL! And by the way, the guy who played Emperor Joseph II really looked like the original's portraits, a little bugeyed:^)). The movie was for artistic (and presumably Hollywood) purposes largely historically erroneous. Salieri and Mozart were competitors when Mozart first moved to Vienna in the early 1780's. Salieri (who's music I've heard a little of, and find it somewhat tedious) had a court position, Wolfgang wanted one. But they ended up becoming pretty friendly, and I don't believe there's any contemporary evidence of Salieri's lingering jealousy.
Salieri did NOT commission the Requiem for the Dead, that was commissioned by a "mysterious", darkly-dressed servant of a wealthy man who wanted to present the piece as his own work and a gift for his mistress! So Salieri did not sit there taking dictation from Mozart on his death bed, although a pal of Mozart's named Sussmayer (who may have fathered one of Wolfgang's kids!, yes, another rumour) probably did so. (Mozart WAS buried in a pauper's grave, the location of which is unknown today). A lot of other things in the movie didn't happen (although some could have, Mozart did have an infantile obsession of sorts with bathroom functions, although when it came to his music he was a serious artist), I've never seen that his wife took his manuscripts to Salieri, I doubt VERY much he made a remark to the Emperor about Hercules shitting marble, although he would have been an early proponent as presenting opera characters as something closer to real people than had been the trend until then, etc.
Many years later, an aged and goofy Salieri in an asylum of sorts DID claim he'd murdered Mozart (poison, I believe), and the Viennese police did look into it (maybe they talked to Mrs. Mozart, who'd remarried and moved away) and found no evidence, naturally, after all those years. But the story lingered: decades later Rimsky-Korsakov wrote a brief opera about Salieri doing the poisoning, and it got to be a rumour that never quite went away (an aunt of mine had heard it and believed it, she told me when the movie came out, although she'd never looked into it). It's guessed now (we'll likely never know for sure) that Mozart died of edema, or rheumatic fever, or maybe trichinosis.
However, I enjoyed the movie so much, I saw it twice in the theatre within a week! (The only movie I've seen more than once in a movie house). The greatest music ever used for background! (Not the same as great background music, which should enhance what's happening on the screen while impinging on conscious listening as little as possible, a tricky thing to achieve).