ok, you're talking about "Elfen Lied", right?
http://anidb.info/perl-bin/animedb.pl?show=anime&aid=1544
there was a OMAKE(yup, fanservice and full of cheesy) after 1st season...
http://isohunt.com/torrents/?ihq=elfen%20lied
well, I was sort of hooked by its OP, and I strongly recommend you all read the manga version after/before watching anime version.
http://anidb.info/perl-bin/animedb.pl?show=anime&aid=4597
For current season, the similiarities of Elfen Lied could be Black Lagoon 2nd Barrage(yeah, the 1st three eps(14,15,16) talked and hinted consequence of child pornography and castrated/psychological-crippled interchangeable loli-shota's ulitmate violence and their survival philosophy...
gunslinger girl is one of my favorite...
http://anidb.info/perl-bin/animedb.pl?show=anime&aid=1002
modified-body stong loli fough for goverment's dirty work, and each of loli's got a "big brother" mentor looked after them...