ameratsu on 15 March 2009
While they are all nice choices, I'd get LittleBigPlanet. Single player is challenging later on and you can play through the entire campaign by yourself, with local or online friends, or a mixture of both. Make sure you have at least a couple LBP fanatics on your friends list so you can browse through and play their hearted levels (their favorites, makes finding great user-made levels extremely easy).
Try to get Valkyria sooner than later, as it seems like it'll become a rarity and it would suck to have to pay above retail for a copy.
Demon's Souls Official Thread | Currently playing: Left 4 Dead 2, LittleBigPlanet 2, Magicka
