By contrast, Defending Your Life is one my favorites.
The two episodes have a lot of similarities. Both address Dean's guilt issues. Both deal specifically with the irrational guilt Dean feels over Ellen and Jo's death. But Defending Your Life works for me, and Sam, Interrupted does not.
Side note: "Manpain" might be a term relevant to this post, but I won't be using it. I don’t get manpain. It’s a Watsonian concept used on a Doylist level and that confuses me. The logic as far as I understand it: Manpain is when a fictional character prioritizes their feelings about another character's victimization over the feelings of the actual character victimized. Bonus points if the character with manpain is a white man and the actual victim is not. So if fictional character has manpain, that’s a bad thing. Fair enough. Fictional characters have flaws. But the next line of reasoning seems to be that stories about male characters with manpain are bad. Not just that there are too many stories about characters with manpain (like there are too many stories about white people). But that these stories are just bad. Always. I used to think manpain was supposed to be a purely Doylist concept, which would make sense, but apparently it's not. It’s Watsonian, or some kind of weird combination. So I don’t get manpain.
Anyway, back to the episodes. In both episodes, a female character who is not exactly human expresses sympathy and empathy for Dean's guilty - a hallucination in Sam, Interrupted, a ghost in Defending Your Life. They express their empathy in similar ways: Dr. Cartwright tells Dean, "I mean, apocalypse or no apocalypse...monsters or no monsters, that's a crushing weight to have on your shoulders. To feel like six billion lives depend on you...God...how do you get up in the morning?" Jo says more simply, "You carry all kinds of crap you don't have to, Dean."
Dr. Cartwright, as Dean's hallucination, is an aspect of Dean's self - first empathizing with him, pointing out the enormity of his burden, and then turning on him and blaming him for a litany of things that weren't his fault, from Ellen and Jo's death to Sam breaking the last seal.
Jo in Defending Your Life is someone outside Dean's psyche, a friend offering reassurance. Instead, Dean's psyche is represented by what happens in the courtroom, where the both the choice of witnesses and ultimate judgment come from Dean's heart. The pattern of Dean feeling the greatest blame for things outside of his control is evident in the two witnesses who appear: He feels guilty for dragging Sam and Jo into the hunting life, two things that were 100% not his fault. His conviction that witness number three would be Amy is an odd one: Amy's death was his direct fault, and a few episodes later he would claim that killing Amy "felt right", and the only related guilt he might be feeling was about lying to Sam.
One of the most striking differences between how these two episodes address the concept of guilt is Sam. Both episodes end with a major revelation from Sam about his internal life. In Sam, Interrupted, Sam informs Dean and the viewers that he feels angry "all the time". While Dean feels guilty about things he can't control, Sam feels the things he's done prove that he's inherently awful. He hallucinates Dean telling him he has a "black spot on your soul". He tells Dean at the end of the episode, "I blame Ruby or the demon blood, but it's not their fault. It's not them. It's me." The alternative to Dean's irrational guilt is Sam's floundering attempts to make sense of the choices he made in S4 and what was and was not his fault, ending the episode with the conclusion that there's something just wrong with him.
Defending Your Life has a very different ending: Sam telling Dean that he doesn't feel guilty anymore. It's not self-justification: He knows what he did, and he's not denying it. "I guess I just finally feel like... my past is my past, and I can move on with my life. You know, hopefully." He admits that he feels good. Sam is presented as a contrast to Dean, someone who is heroic without feeling excessive guilt.
And I think that's why I prefer to the episode. Because it provides an example of a character who is heroic without excessive guilt. People often go by the assumption that the more guilt you feel, the better, and that to be heroic is to be prone to guilt. But it's not that simple. It's better to feel excessive guilt than no guilt at all, but feeling excessive guilt is not a virtue. Dean has a tendency to use his guilt to, paradoxically, feel good about himself, and to convince the people around him to back off when they are calling him on his crap. The mind wipe of Lisa and Ben and his reaction to Sam's criticism of him afterward is a blatant example. Dean seems to believe that guilt and self-loathing are what make someone a good person, and so hates himself to feel better about himself. Watching Defending Your Life, I got a much better sense that the narrative is aware that this logic is BS than I do while watching Sam, Interrupted.