360 for sure.
Everyone I know who owns a Wii is regretting their purchase and find that most games they have bought lack replay value. Wii Sports, Mario Kart Wii, and SSBB are the only games that are played (and they are all Nintendo titles, not third parties). If Wii doesn't get big hits like COD4 or Halo 3, I don't see a wider market than young kids and old adults.
PS3 would go second just because its raw hardware potential is great, and the price isn't bad considering the hardware you're getting (Sony is selling it at a loss). I just have beef against the load times for BD games, but that's all