I think there are legitimately 3 or 4 contenders. Cunha, Agbadou (even though he has only played half the games), RAN, and Andre.
Agba has been key in the turnaround in form since he arrived. We looked like we could concede 3 goals a game before he showed up.
RAN has been a constant source of assists and goals and his form has been pretty consistent all season long.
Andre has been the lynchpin of our midfield and I think he's as good a DM as there is in the PL. It's genuinely shocking when he gives the ball away. He's probably my favourite player in this team.
But POTS is Cunha. He's spectacularly skilful, he's been scoring consistently all season, he's a scorer of good goals and a good goalscorer, even under the GON clownshow, and he is a truly world class player. We'd possibly have been relegated without his contributions.