Sayonara Salvatore is better than the vast majority of SA missions and is the best mission R* ever designed. SA is when the missions started to become linear and the story writing got nonsensical. GTAIII has better sense of place, better villains (Catalina), better world building, better mission design (Salvatore, Waka Gashira Wipeout, assassination missions), higher difficulty curve, open ended missions. Mute character works to the games benefit by making the game about the world and cast of Liberty over some boring ass main character.
SA has more to do and it's a classic for its world and exploration but I put III and VC over it.