I can try and formulate a few reasons that make me enjoy watching anime
A descent anime series is often 24 episode long at least. That gives time to brush an sound moral portrait of the hero(s) which is not easy to do on a film
Often, either you identify yourself to that hero (which is natural) or you have some sympathy for him and his cause...the interesting part of all that is that you don't necessarily start to do that from the first episode
A good scenario would be one able to make you care of the whereabouts of that hero and what will become of his present psychologic or physical condition
From a totally different side, anime has the possibility to brilliantly
mix reality and fiction
Of course, when you put that multi billions budget, you're able to do
so in a modern film but the result is risky and the mixture is not easily accepted (Quentin Tarantino's Killbill is still dividing the cinema (lovers in two camps
Being a cartoon, the anime makes the come and go between fiction the reality natural
Take GTO for exemple, if you had the chance to see both the anime and the drama, you will understand what I mean
Another example is Tonari no Totoro where family bonds are crying natural. However that does not fail the involvement of extraordinary and lovely characters
There is a last and personal reason to watch anime : I love hearing japanese, especially the very formal/rude one
^^
Just Ippun da
Midou Ban