I love Orchid (it's the best Opeth album together with Morningrise IMO), but my fave song is not Apostle.
My faves are In the Mist she was standing, and Twilight is my Robe. I love the ending of Mist (even more incredible when you think about the fact that it is the first song), and I love the raw emotion of Twilight. Akerfeldt sings (growls) his guts out there.
In Morningrise, my fave songs are Silent Water and Black Rose Immortal. To bid you farewell is the icing on an incredibly emotional album, and to me it's even more special because it was the first OPETH song I ever heard... courtesy of some Finnish FTP site some 4 years ago (Who said mp3's were bad: without them, I'd never even hear about OPETH, but I ended up liking the music so much that I had to buy all the CDs).
Anyway, I love Orchid and Morningrise because I can directly relate to the amount of emotion and craftsmanship that Akerfeldt and Co. put into these records (almost 6 years of work right?)... something I can't FULLY say for the latest work. It is good, but not great.