Here is the full list of all 51 Assassin's Creed II trophies - there are 34 bronze, 15 silver, 1 gold and 1 platinum.
Unlock all trophies.
Sweep 5 guards at once by using a Long Weapon.
Stun 4 guards at once by throwing sand in their face.
Kill 10 enemies while remaining in conflict without being hit.
Wear the Auditore cape in each city.
Escape the hideout.
Complete DNA Sequence 14.
Tint your clothes with those colors: Wetland Ebony and Wetland Ivory.
Get all Hidden Blades, Item Pouches and Armor upgrades for Ezio.
Collect all the Feathers.
Complete DNA Sequence 11.
Complete DNA Sequence 10.
Unlock all 20 pieces of Subject 16's video.
Complete DNA Sequence 9.
Discover the Assassin's Tomb inside Santa Maria della Visitazione.
Complete DNA Sequence 8.
Kick a Guard while using the Flying Machine.
Reach 80% of your stronghold's total value.
Discover the Assassin's Tomb inside the Basilica di San Marco.
Complete DNA Sequence 7.
Spend 5000 florins on Courtesans.
Buy a Painting from Florence and Venice.
Complete training and reenter the Animus.
Complete DNA Sequence 6.
Discover the Assassin's Tomb inside the Rocca di Ravaldino fortress.
Complete DNA Sequence 5.
Discover the Assassin's Tomb inside the Torre Grossa.
Intercept a Borgia Courrier.
Perform an Air Assassination on a Poisoned NPC.
Complete your first assassination mission for Lorenzo Il Magnifico.
Complete DNA Sequence 4.
Discover the Assassin's Tomb inside Santa Maria del Fiore (The Duomo).
Discover the Assassin's Tomb inside the catacombs under Santa Maria Novella.
Find the 8 statuettes in Monteriggioni.
Unlock a piece of Subject 16's video.
Use your Eagle Vision to scan a Glyph in the environment.
Upgrade a building in the Stronghold.
Complete DNA Sequence 3.
Complete DNA Sequence 2.
Synchronize 10 View Points.
Complete DNA Sequence 1.
Defend a woman's honor.
Hide 5 dead bodies in a Bale of Hay.
Toss more than 300 florins on the ground.
Win a race against thieves!
Perform a Leap of Faith from the Top of Florence's Giotto's Campanile.
Pickpocket 1000 Florins.
Sprint for 100 meters.
Enter the Animus 2.0.
Break out of Abstergo.
Be reborn as Ezio Auditore Da Firenze.