Well, though I haven't given up on Spore, Viva Pinata is definitely the one that's won me over between the two games. Not surprised by that, either. I never played the 360 game, but this is great fun. The micro managing thus far is very well divvied up -- not too much, not too little. Though it walks you through the basics, it still took me about a half hour before I realized the game's bent. But once you get it, it's pretty damn addictive. I'm not far along at all, but I'm having fun keeping my worm population going in order to feed my owl dudes, and I've got some snake things moving in, as well. This game might look kiddie, but it's got a very fun Zen thing going on that pretty much anyone should be able to enjoy, and the humor is very tongue-in-cheek.
Only thing I could perhaps be critical about is in how slow the camera moves when you're scrolling around the map, but considering the nature of the experience, it fits fine. Also, some of the items in Costolot's aren't labeled and I have no idea what they're for. But Rare definitely has a great formula with this game, nonetheless.