Ok most everyone has probably heard about, seen or even played 1 or all of this series of games.
Assassin's Creed (the 1st)
You play as Altair, a member of the Hashshashin (or Assassins), a real-life group that performed politically-motivated murders between the 11th and 13th centuries. Set in the Middle East during the third crusade, Assassin's Creed is steeped in historical fact. Each of the three main cities was well-researched and beautifully recreated. The nine men Altair is charged with dispatching did, in fact, all die or disappear around the time the game takes place. The attention paid to creating an accurate representation of Jerusalem, Acre, and Damascus is commendable. Were it not for the "anomalies" that flitter around characters, you would have little reason to ever question that this is indeed what these cities and people looked like centuries ago.
It could have been so much better, however the repetitive gameplay elements, and story-heavy title make it a long game to get thru. Not to mention the storyline twist that would be good near end of this story is told to you at the beginning.
over all it gets a 6 out of 10 just because is so damn repetitive, in all aspects.
I do still recommend it if you have not played any of the series, as it will help you get used to the game and allow for hisory to be explained so future parts of series make more sense.