out of the Opeth catalogue, its Morningrise...which, like you, is not my favorite record, but it is mostly because of To Bid You Farewell...which has spawned inspiration for lyrics and reflective stories for me.
Green Carnation's Light of Day, Day of Darkness, i had to special order just to hear the master work...but it was worth it...its a 60+ minute musical journey that is amazing from start to finish.