Here is the full list of all 80 Borderlands: Game of the Year Edition achievements worth 1,750 gamerscore.
Killed 15 enemies with the Berserker's action skill
Killed 15 enemies with the Hunter's action skill
Killed an enemy with the Siren's action skill
Raced around the Ludicrous Speedway in record time
Played with at least two other players.
Killed the Interplanetary Ninja Assassin Claptrap
Killed Commandant Steele-trap
Killed Dr. Ned-trap
Killed General Knoxx-trap
Completed a crazy request for Tannis
Killed each of the loot midgets
Completed all missions in Secret Armory
Killed Crawmerax the Invincible
Reached Level 61
Reached Level 51
Earned level 50
Paid for a worthless tour of the world's largest bullet
Destroyed Lance Depot
Rescued Athena
Destroyed a Lancer while in a Racer
Built the New Car: Monster
Completed each of the larger challenges in all 3 coliseums
Completed the larger challenge in The Angelic Ruins coliseum
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
Earned level 40
I bet you never thought you'd be here
Killed the Vault Boss
Completed all missions in the Rust Commons
Rescued enough Claptraps to earn 42 inventory slots
Killed Flynt
Killed the Rakk Hive
Earned level 30
Killed Krom
Killed 25 enemies with corrosive weapons
Completed 5 missions in the Rust Commons
Completed all missions in the Arid Badlands
Earned level 20
Defeated the Rakk Hive, the Vault Boss, Sledge, Krom, or Flynt in a co-op game
Killed Sledge
Killed 25 enemies with explosive weapons
Equipped a class mod for your character
Killed 25 enemies with shock weapons
Killed an enemy plumber-style
Applied an elemental artifact
Killed 5 Rakk in under 10 seconds
Killed 15 enemies with the Soldier's action skill
Earned level 10
Earned level 5
Completed 5 missions in the Arid Badlands
Emerged victorious from an arena match
Completed 15 missions in co-op
Won a duel against another player
Won a duel without taking damage
Rescued a groupmate from death in a co-op game
Discovered Eridian Promontory
Reached proficiency level 10 with any weapon type
Killed 25 enemies with incendiary weapons
Discovered Crimson Lance Enclave
Discovered Trash Coast
Discovered Krom's Canyon
Killed 25 enemies by ramming them with any vehicle
Discovered The Scrapyard
Discovered Headstone Mine
Discovered Sledge's Safe House
Discovered Skag Gully
Mastered the technology of Pandora
Sold 50 guns to a shop
Completed the "Braaaaaaaaaaaaains!" mission
Killed Ned. Again.
Killed Ned...sort of
Completed the "Jakobs Fodder" mission
Completed the "House of the Ned" mission
Earned $1,000,000
Collected 3 panties, 5 fish in a bag, and 15 pizzas
Collected 5 3D glasses
Collected 15 Claptrap bobbleheads
Found all 6 Claptrap statues
Found 25 oil cans