Just went into Game today to buy a Wii - Saw that they had pre-owned with a year's warranty for £159.99 so figured it was a better deal. Unsuprisingly, got home and the Wii is in mint condition. The only two bits of evidence that it's pre-owned is that there were some Miis on it, and the batteries were low. Everything was in it's protective wrapper, fully put away in a pristeen box.
Preowned Wii with 1 yr warranty - £159.99 (+ £4 of Game Reward points)