I'd have to go with Doom Slayer because his actions speak just as loud as his words could; you know what he wants through every gesture he makes. I feel like that's lacking in most silent protagonists. I would say a character like Isaac Clarke, but he ended up being voiced by Gunner Wright (which I personally think was a fine decision). Now for a little rant, I don't dislike Gordon Freeman, but him as a character feels weird to me because he's just some scientist dude that always saves the day somehow. I understand what Valve was going for, but there's nothing to him that makes me feel he is an entity and there's a bit a gap there to me. At most, he's just a mystery to me.
The point of a silent protagonist most of the time, from what I understand, is to make you feel more immersed in the world as if you're the one in the characters shoes, and as much as I love Half-Life, Gordon Freeman just doesn't really work for me because there are so many questions one can ask about him which I think is an issue (unless there's some hidden story reason behind it that we've never learned). I just think he works as the total opposite as intended, which is to immerse the player if you delve into it. Honestly, I still find it awkward that he won the majority of peoples favorite character of all time on the GameSpot polls years ago. Another one I want to point out is The Point Man from F.E.A.R. He's a bit one dimensional, but I had no issue with him; his silence was fine. I also just wanted to mention F.E.A.R. because it's an awesome game, ha ha.
Anyways, I just wanted to mention more than one, but yeah, Doom Slayer from the 2016 Doom and the upcoming Doom Eternal is my favorite. What about you? Do you have one? I'm not a huge fan of silent protagonists in some types of games so I think that's why Doom Slayer works as he totally has a character to him despite the lack of voice. I don't really have an issue with characters like Link though.