Assassin's Creed II

You play Ezio Auditore, a merchant's son in Renaissance Italy whose comfortable life ends when his father and brothers are executed for a conspiracy he does not yet understand. The game follows him from teenager to seasoned assassin across Florence, Venice, Tuscany and Rome. You climb cathedrals, blend into crowds, and stab targets with a hidden blade. The structure is the same stealth-and-traversal loop the series ran into the ground later, but here it is fresh and tuned, wrapped around a real revenge story with Leonardo da Vinci as a friend who builds your gadgets. It is the entry that made the whole franchise work.