I'm a fan, too. Siglo VI, Magicos and Robustos are my most frequent selections. I recently rekindled my admiration of the Lanceros - I have a box from 2010 and they are sublime; and I always enjoy a Siglo IV with a bit of age on it.
While I enjoy the occasional Siglo II, I sometimes think a purchase of the smaller sizes can be difficult to justify from a bang per buck perspective. On balance, however, I'm rarely disappointed.