The best monsters are fresh monsters. Not only because familiarity breeds contempt (which is true), but also because the GM is forced to describe the monster without the crutch of shared understanding. If I tell my players they encounter orcs, then they will understand what I’m telling them, but the inherent “otherness” of orcs won’t impact them. They probably won’t even take the time to imagine what the orcs look like. But if the monster the players encounter is one they’ve never heard of before, the GM is forced to do a little more descriptive work, which ultimately makes the game better I think.
There will always be room for the classics, though. In my mind, the natural progression of monsters is to start out as terrifying creatures. As we become more used to seeing those monsters, they become a little less scary and a little more relatable. The minotaur is a good example of this, I think.
While still able to pull its weight as a monster (and they are one of my favorite classic monsters), I more often use minotaurs as exotic NPCs these days. This painting by Paul Reid gives the viewer a look at the minotaur when it’s not menacing Athenians. It looks almost normal.
I’d absolutely recommend looking at Paul Reid’s gallery, linked above. He works in a classical style which I think is significantly underrated by modern artists. And he’s done a lot of work with classical mythology, including several different takes on the piece above.