The Top Ten Most Challenging Xbox 360 Achievements of All Time (So Far)

Neuf -- 09: Dead Rising "7 Day Survivor" (20 G)

Required Actions: Survive for at least 7 days.

Requiring a minimum of fourteen hours of non-stop game play to unlock, this one has the gamer targeting and attacking survivors while avoiding confrontations with zombies in order to harvest the food items that the survivors carry so that they can stay alive -- and healthy -- for seven in-game days.

Perhaps the most challenging Achievement in the game, it requires that the player master the fighting system (so that they take as little damage in battles as possible) and obtain all three of the Health Books -- while finding places to hide in between raiding the randomly-spawning survivor groups!

Considering that only an average of 5% of the gamers who play this game have unlocked this one, it certainly qualifies as a tough Achievement.