I preferred the smallish-con atmosphere of AnimeFest, to be honest (past tense is used purposely), but I love the variety of programming that A-Kon has to offer.
From your avatar, I imagine you are a cosplayer--I will say that the Anatole is absolutely STUNNING for cosplay photography. There's enough size and variety in that hotel to suit just about anything.
I have heard excellent things about the organization of Ikkicon and the cosplay level of Anime Matsuri. Realmscon has a good gaming setup if you're into that.