Tom Waits - I can "hear" why his music is appreciated, but it has never really touched me. Just some drunk growling to bad coumtry music.

Pink Floyd - In terms of songwriting and dynamics, nothing gets past them, but most of their music sounds so thin and distant, never really got it.

Ministry - Tried so many times to get into them, I don't know if it's Al's voice or their music, just doesn't happen.

Converge/Dillinger Escape Plan - Any --core music for me is gut music not "head" music.