I hate them all, but I'd say Manaphy, is the best-looking one (and Phione, it's a pity it won't evolve into Manaphy).
Darkrai is pretty cool. No weaknesses
Palkia. The shape of his head is funny
LOL, i think i know what ya mean.
I would have to go Darkrai, it's the first dark type pokemon, even though you would think it is a ghost by appearance and what it does, with nightmares.It looks pretty intimidating too.
I hate choosing! D=
I love Dialga, Giratina AND Darkrai!
I suppose if I HAD to choose one, I suppose I'd go with Giratina, I love the whole Ghost/Dragon type idea and it's become more deadly now with it's Origin Forme.
Shaymin, but I´m not sure, Darkrai is as good as Giratina for me.
I think Cresselia is best cause i like the colours and it just looks awesome:)