I love Empiricism, but it seems to be shunned by most Borknagar fans.
That said, The Olden Domain has risen to the top of the list for me. I used to love Quintessence the most, but the pagan/folk aspect of The Olden Domain and Garm's vocals have steadily increased its level. I can listen to the entire thing without ever feeling bored or skipping a track.
fuck those bands. especially rumpelstiltskin grinder. when i saw absu, my girl asked who was going to open up, i even felt embarassed to say that name, its terrible, not to mention the music itself