It may seem like blasphemy, but there are some songs that The Smiths recorded that were either produced poorly or have been vastly improved in concert.
I would go with "Shakespeare's Sister" because I think that the production is god-awful. With the right production values, it could have been a huge hit. Not to mention the entire "Kill Uncle" album (w/ complete Rockabilly backing!).
What do you think?
EDIT: Feel free to include solo songs as well. Forgot to mention that.