Troll thread seems to be working well enough here.
In any case, to take OP seriously for one I'd say this is one example of the anime being better then the manga. However, I can't watch Elfen Lied twice, god help me I tried to watch it again but the ham-handed over the top YOU SHOULD FEEL BAD FOR THIS CHARACTER, HER LIFE SUCK elements of it get on my nerves. It goes out of it's way to shit on every character so you can call it deep, then throws in fan service and violence almost as a reward for putting up with it's crap, only to move on to the next character to shit on.
Interesting idea, but the plot gets pretty retarded, the ending sucks (but I'll admit that they could have done worse, this isn't really something to be proud of) and on the whole it's just overrated in the anime community.
tl;dr - shit sux. If you want to watch a 'deep' anime, watch Eva or something.