Boy, that's a tough call wai. I'd probably say you definitely picked the top three toughest ones for your list there, but of the bunch, I couldn't guess which is the rarest. I'd say that the Freeze Frame Weequay has gotten the most publicity of the 3, and unless things have changed recently, I think it generally sold for the highest price too - usually $200+ back when I was keeping an eye on it. So that would be my uneducated guess at it.
Someone else who's got more up to date information might have a more accurate idea though, since I haven't paid much attention to the POTF2 line in the last year or two...