@Phear: I think Pirates' Carnival is totally worth it. I have been playing my boyfriend's copy of it obsessively, and I finally unlocked all the captain cards, although it took FOREVER. I also found the Kaya card. Very fun. 
Quick overview in my own words:
It's a "board game", but not like Mario Party. On this board, each of four characters (chosen from the Mugiwara Kaizokudan) take turns selecting spaces on the "board". There are boards for East Blue, Grandline, Alabastaa, Skypiea, and the island from the Foxy arc which name escapes me right now. You can surround other spaces owned by other players to steal them, or you can just get spaces one at a time by selecting.
Some spaces cause "status" effects to the board. I.e., Vivi gives you another turn, Aokiji (sp?) freezes a space for a turn, etc. Some things just randomly happen, too; for instance, in the Skypiea board only, Ener randomly zaps two spaces away from random players.
Other spaces are the "minor" characters, and you get to pick from three of the "general" minigames. Some of these include a "find Pandaman" game, a kung-fu dugong fighting game, shooting islands from the cannon of the Merry, climbing the mountain on Drum Island, etc.
Finally, there are "captain cards" in some spaces. These are major characters from the series, and when you get their cards, they "join your crew" (but they can rebel or get taken by other players who surround them with their own spaces). These characters all have their own games. Some of these are a "fight Buggy by jumping on his head" game, defending the Going Merry from Wiper, Arlong lawn darts, etc.
Sorry for the length there. ^^;; A little more on topic… I -really- don't want America to get this game. I don't know whether I'd be more upset if they cut out Skypiea (with which I have a deep, deep obsession) or if they gave voices to the characters from it. x.x
I do reccommend the Japanese version of the game though. 