I'm still thinking of songs I have been obsessed with in the past, since my music obsessions always revolve around individual songs rather than bands or genres, and this one came to mind...
The Damned - "Alone Again Or"
(A high fidelity video!! Much better than the one I saw several years ago.)
Damn, I like this song. It's the only song by The Damned that I like (I think, since I doubt I've heard them all). My recollection is that their other songs sound very different than this one. I love the acoustic guitar in this piece.
The Damned - Alone Again Or (1987) - YouTube