I don’t mind a decent silent protagonist. If the rest of the game is expressive enough, it’ll be fine.
Caim from Drakengard 1 is a favorite. He starts off with a voice, but that changes due to some plot reasons. You still get a great sense of his character through his actions-- which tend to be of the violent, merciless sort.
The Persona 2 duology is an interesting one. Tatsuya is silent for the first part, but it doesn’t detract from his character because his character (in Innocent Sin) is cool, detached, and stoic. Silent protagonist suits him well. When he starts talking as a side character in Eternal Punishment, you already know his circumstances, so his change is welcome. Unfortunately, Maya Amano goes silent in EP-- Such a loss is felt because we already know her as the ever-so-cheerful big sister with a charming catchphrase to boot.
I believe ZHP: Unlosing Ranger Man vs Dark Death Evil Lord had an interesting explanation for it’s silent hero. If I remember right, the hero was traumatized and so they went silent because of their abuse. It’s a heart-tugging little detail that fits the themes of the game well.