I'm looking for a cute co-op game to play with my wife and found Overcooked. If I can only play one, does it make more sense to go with Overcooked or Overcooked 2?
It makes more sense to go with Overcooked 2. It's longer, has more levels, more content and more features.
Also because it has online co-op (Overcooked 1 only has local co-op). (I don't think this matters to you because you're probably going to play couch co-op with your wife, but I want to add it for the general answer).
If you can only purchase one title, get Overcooked: All You Can Eat instead of either of the original games. It’s a remastered compilation of both games, with an enormous amount of additional content.