I'm really liking trying to get Broons Bane down by Rush. It's not too elaborate but is a challenge for me with the advancing bass note that seems to come around at the end of each arpeggiated chord before I'm ready for it lol. Beautiful Cm13 chord in it too. Actually now that I think about it, my #1 favorite is probably Steve Morse Modoc. That took forever to learn but is SO gratifying to be able to play it and even then takes about 3 or 4 passes before getting it...Its stuff like that that you can truly see the value of knowing theory to able to write something like that I think too.