Go LOKI!

I love alliteration so...

Odin actually raised him, while Laufey left him to die. Even if Loki was Loki Laufejarson in Eddic poetry, in the film he is more Odin's son.

Thank you Aerinea!

Odin wasn't his real father, and he compared him to Thor too much :/

I would never say this to Loki's face if I knew him, but this one has a ring to it. xD

A) alliteration
B) he does not acknowledge Odin as his father anymore

Loki Odinson, he would have died if he hadn't been "saved" by Odin.

Odin raised him. If I ever adopt a kid, he/she would be MY kid, you know? Once adopted the child is considered part of me. So, it really doesn't matter what his 'biological' relation is. Being a parent doesn't mean having a child and that's it, it's bringing up that child and caring for them. Odin adopted him and raised him, therefore he is an Odinson. Plus, Loki might not acknowledge Odin as his father anymore (which I don't believe to be true), but Loki has never considered Laufey as his father, even after finding out.
Edit: Sorry If I sound defensive to anyone. I just feel strongly about it because my brother is adopted, but he is my brother no matter what, and to say that Loki shouldn't be considered an Odinson just because he isn't 'blood,' is really messed up and offensive. :/

It sounds better XD