The Top 10 Most Challenging Achievements: Xbox 360

07. Hitman Contracts: 5 Professional Silent Assassins (45G) Get 5 Silent Assassin ratings on Professional difficulty.

The Hitman game series has such a wide and massive following that it doesn't seem credible that it should be necessary to explain the premise to anyone - and yet it is!

In a nutshell you play as Agent 47 - the game's protagonist who is is a bespoken genetically engineered clone that was created in a lab in the Eastern European nation of Elbonia (OK I made that country up - it was probably actually Romania or Hungary but still, Elbonia sounds so much better).

The goal for this genetics experimentation was to create the perfect assassin - and after a very large string of failures they actually managed to do it - by creating YOU!

Unfortunately for them they did too good a job, so in addition to being the perfect assassin and being able to acquire trivial skills like a bazillion ways to kill, fluency in foreign languages, that sort of thing, you also acquired a distinct morality and self-awareness that caused you to part company with your creators.

Unfortunately killing is the only thing you really know how to do and are good at, so in the role of Agent 47 you let yourself be recruited by The Agency as a freelance hitman.

You are paid very well to pull off some of the most spectacular hits in history, establishing a reputation for being a Ghost for your chameleon-like ability to slip in, do the job, and then slip out without being ID'd or setting off alarms...

While each of the games in the series has a slightly different set of requirements for earning the Silent Assassin rating, for Contracts to do it means that you complete the mission while never being fully detected or caught on film; you don't trigger alarms; you leave no evidence behind; you accomplish your contract by killing no more than two people - one of which must be the target!.

The thing is, obtaining the Silent Assassin rating for five missions while you have the game set to the Professional difficulty? That is a very challenging proposition for most gamers...

As you can see from the example video above, it means seeking out the path of peace and not being all confrontational. It means abandoning your guns, and relying on your trusty syinge for non-lethal takedowns, and your garrotte -- or environmental opportunities -- for the lethal ones, with the appearance of an accidental death being preferable to an obvious hit.

While certain missions in the game lend themselves to that approach, there are not five of them that really do - only three - so for two of the irregular ones you are going to really have to work hard at it - which is why this Achievement made the list and is so challenging!