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