Every person who has an Xbox 360 has come to love the dulcet tones of the “Achievement Unlocked” tone. In some cases it represents something for nothing, a token piece of fluff tucked into a game by a lazy designer, but in other cases, it represents hours and hours of virtual (and sometimes real) blood, sweat and tears.

It is these achievements we celebrate, and warn you of, in this week’s edition of the Top Ten. Ladies and gentlemen, here are the ten achievements guaranteed to set your controller aloft as you strive to boost your Gamerscore into the stratosphere.

10. “Mile High Club” – Call of Duty 4

“Sky dive to safety on Veteran difficulty.”

Sounds easy right? I mean, how hard can it be? You just have to jump out of a plane and let gravity do the rest. Yeah, not quite. Try taking on an entire plane full of terrorists on the hardest difficulty level of the game, culminating in a hostage rescue as your intended target hides behind his hostage. Oh, did I mention that you have to do the whole thing in less than 60 seconds? You only have flash bangs too, because airplanes tend to not react well to explosive devices. Have fun!

9. “Aperture Scientist” – Portal

“Earn gold medals on all Portal challenges.”

Everyone who loves Portal does so because they haven’t tried to do this achievement. Those who have attempted to get a gold medal on the challenges: fewest portals, fewest steps and shortest time on all six challenge maps, know that Portal isn’t a genre busting game sent to deliver us from video game mediocrity but instead is a tool of Satan sent to subjugate our wills.

Oh sure, you can watch YouTube videos to see how to do the challenges, but I can watch someone perform brain surgery on YouTube and I’m pretty sure you don’t want me mucking around in your melon.