I have "The serpents egg", "AION", "Into the labyrinth" and "Spiritchaser" and I think "Spiritchaser is the best", then TSE, "Aion" and ITL.
I think "Spiritchaser" is superb, although I must admit that it's a record that has quickly found a safe spot on the shelf. "Spiritchaser" is a bit more ethnic than the other albums I have and this may also be why I prefer it and of course because I think the songwriting is better than the rest!
The reason why I think "Into the labyrinth" is the worst, although it's still cool, is mainly due to all the synthetic electronic shit that's on. In many cases it kind of destroys the songs. For instance the keyboard on "The carnival is over" or the drums on "The ubiquitous mr. lovegroove". I even think "The carnival is over" is one of the best songs on the lp, but it could have been better if it hadn't sounded so synthetic!
Dead Can Dance is one of the only bands, besides some metal shit, released after 1981 that I listen to, although I must admit that it's rarely that I listen to their records.