IMO there is 2 categories of opeth fans. Those of the years 2000 and those of the 90's. For the first category, their heart should go for Still Life. Probably because they discover Opeth by listening to more popular, harder, strogner group in the metal scene. For those that are with Opeth since the debut, Morningrise remains and will always remain at the top of our heart. So, in my own, i'll say Morningrise is the best one...