Full list of all 44 Assassin's Creed achievements worth 1,000 gamerscore. It takes around 20-25 hours to unlock all of the achievements on Xbox 360.
Achievements they've won
Achievements they've not won
You've slain Tamir, Black Market Merchant in Damascus.
Use Scholar blending 20 times.
Find All of Richard's Flags in the Kingdom.
Find All Flags in Jerusalem.
See 85% of all the memory glitches.
Go through every dialog with Lucy.
Find All Teutonic Flags in Acre.
Find All Flags in Damascus.
Find all Templar Flags in Acre.
Kill every Templar.
Kill one of your main targets like a true assassin.
Find All Flags in Masyaf.
Grab and Throw 25 Harassers.
Find All Hospitalier Flags in Acre.
Complete all Reach High Points.
Complete every free mission in Acre.
Complete every free mission in Jerusalem.
Pickpocket 200 throwing knives.
Kill 75 guards by throwing knives.
Complete Assassin's Creed.
A strange vision has appeared to you. What could it mean?
Have a complete Synchronization bar.
You've slain Robert de Sable, but there is one more...
Complete every free mission in Damascus.
Assassinate all your targets with a full DNA bar.
You've slain Majd Addin, Regent of Jerusalem.
You've slain William of Montferrat, Liege-Lord of Acre.
You've slain Sibrand, the Teutonic Leader of Acre.
You've slain Jubair, the Scribe of Damascus.
Last 10 minutes in open conflict.
Assassinate 100 guards.
Defeat 25 guards in a single fight.
Perform 50 Combo Kills in Fights.
Perform 50 stealth assassinations.
Perform 50 leap of faith.
Jump through 20 merchant stands.
You've slain Garnier de Naplouse, Hospitalier Leader in Acre.
You've slain Talal, Slave Trader of Jerusalem.
You've slain Abul Nuqoud, Merchant King of Damascus.
Defeat 100 opponents without dying.
Perform 100 Counter Kill in Fights.
You've protected Masyaf from the Templar invasion.
You have found the traitor and have brought him before Al Mualim.
You've successfully completed the Animus tutorial.