Any of the Neo Geo shooters and run n' gun games like Aero Fighters 2, Metal Slug or Shock Troopers. They also have Burning Fight and Mutation Nation which are great brawlers. Also Overcooked is a lot of fun.
Fire emblem warriors is one of the best, First 3 misisons are single player but the rest of the game is all coop. So awesome cause i did with a buddy of mine.