favourite opeth acoustic riff ?

The acoustic intro to The Moor. Right after the trippy slide part fades out and the classical guitar part starts up.....WOW.
 
you gotta go with blackwater park interlude...that is an awesome riff...and while your talking about acoustic riffs....im not sure but i think all the cool riffs on closure are acoustic. also the first acoustic break after the intro on "when" very early in the song, its very short but very sweet :worship: