I like all DS songs, I think it's the band that has made no really bad songs.
I struggle to find weak points.
So I was thinking these days about the five songs that I consider the worst, including b-sides, ITILYTM, Going Home or What's the matter baby.
The five that don't leave me completely satisfied are in my opinion:
My parties, the worst
Southbound again, I like it but it's not fully developed (better live in rainbow),
Two young lovers (much better live versions)
Iron Hand, too poor arrangement, not very refined
Kingdom come.