Full list of all 81 Borderlands trophies - 59 bronze, 17 silver, 4 gold and 1 platinum.
The base game contains 51 trophies, and there are 5 DLC packs containing 30 trophies.
You have defeated all bosses and are a powerful force to be reckoned with
Killed an enemy with the Siren's action skill
Killed 15 enemies with the Berserker's action skill
Played in a co-op game with either an employee of Gearbox or someone who had this trophy
Killed 15 enemies with the Hunter's action skill
Completed 15 missions in co-op
Earned level 50
Earned level 40
Defeated the Rakk Hive, the Vault Boss, Sledge, Krom, or Flynt in a co-op game
Killed the Vault Boss
Discovered Eridian Promontory
Discovered Crimson Lance Enclave
Completed all missions in the Rust Commons
Rescued enough Claptraps to earn 42 inventory slots
Killed Flynt
Killed the Rakk Hive
Emerged victorious from an arena match
Rescued a groupmate from death in a co-op game
Won a duel against another player
Won a duel without taking damage
Discovered Trash Coast
Mastered the technology of Pandora
Killed 25 enemies with corrosive weapons
Killed 25 enemies with shock weapons
Killed Krom
Earned level 30
Discovered Krom's Canyon
I bet you never thought you'd be here
Discovered The Scrapyard
Completed 5 missions in the Rust Commons
Earned $1,000,000
Killed 25 enemies with incendiary weapons
Raced around the Ludicrous Speedway in record time
Completed all missions in the Arid Badlands
Equipped a class mod for your character
Killed Sledge
Earned level 20
Killed 25 enemies with explosive weapons
Discovered Headstone Mine
Killed an enemy plumber-style
Reached proficiency level 10 with any weapon type
Discovered Sledge's Safe House
Applied an elemental artifact
Sold 50 guns to a shop
Killed 5 Rakk in under 10 seconds
Killed 25 enemies by ramming them with any vehicle
Killed 15 enemies with the Soldier's action skill
Earned level 10
Discovered Skag Gully
Earned level 5
Completed 5 missions in the Arid Badlands
Collected 3 panties, 5 fish in a bag, and 15 pizzas
Collected 15 Claptrap bobbleheads
Found 25 oil cans
Killed the Interplanatary Ninja Assassin Claptrap
Killed Commandant Steele-trap
Killed Dr. Ned-trap
Found all 6 Claptrap statues
Killed General Knoxx-trap
Completed a crazy request for Tannis
Collected 5 3D glasses
Completed the larger challenge in The Angelic Ruins coliseum
Completed each of the larger challenges in all 3 coliseums
Completed the larger challenge in the Hell-Burbia coliseum
Completed the larger challenge in The Gully coliseum
Completed the lesser challenge in all 3 coliseums
Completed all missions in Secret Armory
Killed Crawmerax the Invincible
Reached Level 61
Destroyed Lance Depot
Killed each of the loot midgets
Rescued Athena
Paid for a worthless tour of the world's largest bullet
Destroyed a Lancer while in a Racer
Built the New Car: Monster
Killed Ned. Again.
Killed Ned...sort of
Completed the "Jakobs Fodder" mission
Completed the "Braaaaaaaaaaaaains!" mission
Completed the "House of the Ned" mission
Reached Level 51