Kirby's Adventure Wii. I regret never doing the research on it. My kids completed it over 4 days and thought it was rubbish.
Second one was the 3DS - why? Because I gave birth 8 years and 3 weeks prior to the release of the 3DS XL, so the inevitable birthday present was only the 3DS. He was never going to wait!
(actually, it's a great purchase, but at the time I really wanted to get the XL)