Uncharted.
The story is simple, a REGULAR guy(they say he's a regular guy, but he looks like he does this for a living),named Nathan Drake, he is believed to be the decendant of Sir Francis Drake, is in search of his treasure, along the way you collect certain hidden treasures, that if you collect enough you will be able to unlock certain costumes, or bonus stuff.
The game would be easy if it wasn't for the darn shooting ability, that will leave you frustrated during gun battles. The health of your player can also go down really fast which can make this game a little more difficult for this game.
Its a good game and a must buy for action/adventure fans.