Godhead's Lament and Nectar hold high sentimental value because they were the first two I ever heard. But I would have to say their bet songs musically would have to be Apostle In Triumph, Black Rose Immortal, April Ethereal, When, The Moor, Moonlpase Vertigo, White Cluster, The Drapery Falls, and Bleak. Most emotional woul be Forest Of October, Night And The Silent Water, To Bid You Farewell, the two MAYH songs lsited earlier, and just about all the rest...see how disrespctful it would be towards Opeth to limit it to just one.
NP: Aghora - Satya, a must for Cynics everywhere...