Most atmospheric Opeth song?

Karma
Credence
When
Epilogue
Dirge For November
To Bid You Farewell

btw. Weakness is by far the worst Opeth track imho
 
Madrigal. No contest. I really wish Opeth would capitalise more on the emotions that can be gained from a sparse little song such as this and apply them to their main tracks. I would love to see a bit of atmosphere-evoking minimalism in there.