I voted for Red Dead Redemption 2, though it would probably be Spider-man or God of War if I had a PS4.
A few days ago I might have voted for Sea of Thieves but I was able to check out the "final beta" this weekend and found it incredibly dull. Even playing along with two silly friends, it got old fast. The combat/shooting is dreadful and repetitive.
I'll still check it out since it's included in Xbox Game Pass. I'm hopeful that with a little more time spent with the mechanics and if we unlock more interesting quests and gear that the game will have some fun to offer.