all of these games are on my xmas list for when i actually have some money, so i will end up owning them all. but it depends really, they are all very different games.
all very good games too. have you played all of them? or any of them?
F Zero GX is really good game, but the storyline is short. It is best used as a multiplayer game. I would recommend Soul Calibar 2 for the gameplay. That is the kind of game you won't get tired of for a while.