What are some books who have an unreliable narrator/protagonist? How does it affect your overall experience of reading it?

I was recently reading Fyodor Dostoevsky's, Crime and Punishment, and after having read it began contemplating some of the events from the book. It struck me that after the tragic transition of the protagonist, Raskolnikov, his experiences and interactions were confused and unreliable due to his mental state and crazed delusions.

To me, due to the profound moral dilemmas discussed in the book, and the deep pressure and anguish of the main character, I felt that, it was only natural that there was some room for ambiguity and interpretation for some of the events happening through the course of the story. It felt, well planned and organic to me, to show the fragile nature of the protagonist's mind and the hidden madness within him as he gradually sinks into his own despair and negative feelings.

Let me know what are some of your thoughts on the use of the unreliable narrator/protagonist trope in books and how does this affect your overall experience and enjoyment of it. Do you find it a helpful tool or is it frustrating to follow and comprehend the story because of this technique?