All About My Wife - I know you aren't looking for a cute romance, and it's really not despite the happy ending. It's just an interesting take on infidelity. The main guy hires this other guy to seduce his wife so he can divorce her because she's awful. The wife falls for the other guy and becomes a better person. The main guy regrets it. She finds out that her love for the other guy is only there because he knew everything about her because of the husband. They reconcile in the end.
Happy End - Woman starts cheating on her husband who's gone into a depression because he lost his job. The ending is great.
