Sad/tragic endings.. none. If I have liked the film then I've always revisited.
On the top of my mind, I can only recall Assamese gem called Calendar. But the only reason I haven't re-watched it is because it isn't available on any streaming format for me to watch or atleast I haven't found out. And I loved this film & cannot wait to have it in my collection.
The films with sad/endings which I didn't like & me not liking being the reason for not rewatching it then that'll have many films. For example the recent Kannada film Dia which I never connected & highly disliked. In recent times, it is the epitome of sadness with every major character being suicidal or die in an accident. With suicide being promoted as the direct solution for every problem.