This debate raged for decades in the interactive fiction community, and it was never properly settled. Main characters with strong personalities simply became the default over time, due to highly influential authors. Same in graphic adventures, for that matter. And in strategy games, ever since they started to acquire RPG elements. But in more... active game genres? Some of the most famous and beloved main characters ever have been silent: Doom Guy. Gordon Freeman. Link. (One of them is not like the others.) Only the titular Duke Nukem was a wise-ass, and that infamously aged very poorly. But as for which kind is better?
Let's put it this way: imagine Sam&Max if the titular characters were the silent, brooding types. Conversely, imagine if the unnamed main character of Myst made funny voices at the drop of a hat and messed up the place every time you clicked something unimportant. It really depends on the game.