>>6677424>You can still pick up all the entire line for retail price.Not entirely true, though close enough if you really want to get them I guess.
As far as underrated themes go, I have always been a fan of the underwater themes. Aquazone is an obvious classic, but the newer themes aren't bad either.
Atlantis had sets with really nice parts. And the more recent Deep Sea Explorers City subtheme had some more realistic underwater sets.