2. The Perfect Run - Super Mario Galaxy 2 (Wii)
http://www.youtube.com/watch?v=745zKLijKg8 If you know that you're not a very patient person, you'd do well to never attempt "The Perfect Run" in Nintendo's otherwise excellent and wonderful Super Mario Galaxy 2 - for the sake of your brain function, at least. Having collected every other star over the course of the game (there's 242 in all), it's up to Mario to navigate an impossibly ridiculous series of challenges in this final stage, one which tests all the skills you've learned as you're hurled between platforms and made to dodge things over and over again. The killer is that you can't get hit - not even once - and the slightest mis-judged movement means game over. Video games these days are generally much easier than they used to be, so it's kind of nice that Nintendo included this soul-crushing level of stomach-crunching hell as a reference to the glory days. For completists, it's essential. For anyone else, it's like a punch in the face from Shigeru Miyamoto.