I prefer single player. I have had enough with other people slaying me, when I am working on to level up. Used to play Diablo online with multiple other on the internet. But they just came to slay me for no reason what so ever, just to bee idiots, and they where like in level 25 and 35, and i was just on level 12 minding my own game and business. I did not even bother others game playing. So no, never liked multiplayer online games after that... So i stick to single player games, where no warmongering idiot comes to kill you for no parent reason what so ever.
I can enjoy both actually. I play alot of Minecraft aswell both singleplayer and multiplayer. I also play Overwatch, always with friends. Some Cities: Skylines too. That's just few of the games, and i can't forget to mention NHL 18 on xbox one :D