This is kinda a tough question.
As for what gets the most play time in my house, that's the Wii by far as my kids only play the Wii. However, I play whichever system (Wii, PS3, or PC) I currently have the latest game for.
I mean, when I had no brand new games and nothing to specifically beat, I played various games equally and maybe BF2142 on PC or Civ4 on PC a bit more. When I bought NSMBWii, I was glued to my Wii. Now that I just bought a PS3, I've been playing my Assassin's Creed and Flow.
Personally, I still voted for Wii as the Nintendo games are still my top choice. Regardless of what launches when, if given a choice I'd always pick Zelda, Mario, or Metroid over any other.