I've payed a whole lot for fully priced games that I only ever played for two or three hours then never touched again. The 3DS Donkey Kong game is one of those I particularly remember, Luigi's Mansion 2 and a few others as well. Most of the Legend of Zelda games though I actually got a fair bit further with those and revisited Ocarina of Time 3D when I was older and grasped the game a lot better... yeah, I was a kid back then, no wonder I never got far in any of the games.
Other than those, I spent a copious amount on Skylanders at that age as well, up until and including Swap Force I made a habit of buying every of those overpriced pieces of trash they brought out. Must've spent around a thousand pounds or more on the series as a whole. Now, almost a decade after I got into the series, I'm really beginning to realise how much a colossal waste of money that whole toys-to-life gimmick was.