You need to go back further! 'Crystal Tears' is a good album (and I agree, its follow-ups are inferior versions of it), but its predecessor, 'Orama' is a desert-island album for me. The production is odd, but it's oddly brilliant, and gives the whole thing an atmospheric cohesion and uniqueness that was lost once they shifted to the more simplified and standard goth-rock style of 'Crystal Tears' and its follow-ups.
In other news, it's interesting to note that almost all the bands mentioned in this thread are a lot more depressive/atmospheric than Sentenced. I love Sentenced, but they're pretty much a pop-rock band (in their latter days), who happens to have a lot of suicidal lyrics.
Neil