the Lego games. They're not at all difficult, yet still fun and quite humorous at times.
My wife and I went through the bulk of them, but I think that Lego Star Wars (1 &2) are the best of the bunch followed from Lego Batman. I like how the later ones do a dynamic split screen when both players move away from each other but it also makes the game a little too open and sometimes makes it difficult to know what you're supposed to do in the later games. We'd get annoyed and revert to single player.
We tried Lego Lord of the Rings and they've just pulled audio from the movies, there is some humor but I think the humor worked best when they were forced to mime a known story instead of just pulling the audio from the film itself.
That said, Lego City Undercover is pretty good. There is speach throughout but it is an original story while making nodes to various police, spy, firefighter films and TV series. It is single player and I think most of the newer Lego Games seem to be better geared to single player experiences, which is odd considering they have technology that handles split screen.)