Hitman: Blood Money (Xbox 360, 2006)

This title truly defines the meaning of stealth assassin. Since you can change out of the usual black suit and red tie; into the clothing of the bad guys; from chefs to police officers or whoever else may be stupid enough to go near the bushes. Also there are literally 100 ways to kill a client. You could take the easy route with a long distance sniper rifle or you could get up close and personal with a silenced pistol. Or perhaps your the die hard type; running blindly into combat blasting a fully automatic sub machine gun. At any rate from knives to guns to bombs; Agent 47 is the greatest assassin of all time...no offense to Altair fans.