Here,are my 2:
Rock'n Roll Suicide (awesome mini opera in 3 minutes)
Heroes (I really would like to kow what he took when he had the inspiration for this one)
Let me add,especially impressive when you consider the era these were written,everyone was playing most boring 10 minutes guitar soli.
Not Bowie but same category - Edgar Broughton Band,Evening over rooftops,just inspired.