Probably a darkhorse at best but...
CostCo.
Major releases are always stocked and usually $5-$10 cheaper than everyone else. I got Mass Effect there day after release for $53 new.
They almost always have consoles in stock, Wii's included, and the bundles they do sell are genuinely worth it.
My 360 cost $50 more than regular retailers and came with a 2nd wireless controller, extra headphones and a play and charge kit.
They even bundle up games - Mercury Meltdown Revoltion and Rampage for the Wii for $24.99 (if memory serves). Which is a great deal if those are games you wanted, like I did.
The only real downside to them is they don't stock a variety of games. But, your big releases (Gears of War, Mass Effect, Halo3, Madden, etc) are always in stock and almost always $5 cheaper.