Full list of all 80 Borderlands Game of the Year Enhanced achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Killed 15 enemies with the Berserker's action skill
Killed 15 enemies with the Hunter's action skill
Collected 15 Claptrap bobbleheads
Collected 3 panties, 5 fish in a bag, and 15 pizzas
Found 25 oil cans
Completed a crazy request for Tannis
Killed the Interplanetary Ninja Assassin Claptrap
Killed Commandant Steele-trap
Killed Dr. Ned-trap
Killed General Knoxx-trap
Killed the Vault Boss
Completed all missions in the Rust Commons
Discovered Crimson Lance Enclave
Killed Flynt
Killed the Rakk Hive
Discovered Trash Coast
Killed Krom
Discovered Krom's Canyon
I bet you never thought you'd be here
Discovered Eridian Promontory
Killed Crawmerax the Invincible
Destroyed a Lancer while in a Racer
Paid for a worthless tour of the world's largest bullet
Killed each of the loot midgets
Killed an enemy with the Siren's action skill
Completed the "House of the Ned" mission
Completed the "Jakobs Fodder" mission
Killed Ned...sort of
Killed Ned. Again.
Completed the "Braaaaaaaaaaaaains!" mission
Completed all missions in Secret Armory
Earned level 30
Earned level 40
Earned level 50
Reached proficiency level 10 with any weapon type
Rescued enough Claptraps to earn 42 inventory slots
Completed the lesser challenge in all 3 coliseums
Completed the larger challenge in the Hell-Burbia coliseum
Completed the larger challenge in The Angelic Ruins coliseum
Completed the larger challenge in The Gully coliseum
Completed each of the larger challenges in all 3 coliseums
Built the New Car: Monster
Rescued Athena
Destroyed Lance Depot
Reached Level 61
Found all 6 Claptrap statues
Collected 5 3D glasses
Reached Level 51
Killed 25 enemies with shock weapons
Discovered The Scrapyard
Completed 5 missions in the Rust Commons
Killed 25 enemies with corrosive weapons
Raced around the Ludicrous Speedway in record time
Earned level 20
Completed all missions in the Arid Badlands
Equipped a class mod for your character
Defeated the Rakk Hive, the Vault Boss, Sledge, Krom, or Flynt in a co-op game
Killed Sledge
Discovered Headstone Mine
Sold 50 guns to a shop
Discovered Sledge's Safe House
Mastered the technology of Pandora
Killed 25 enemies with explosive weapons
Killed 25 enemies with incendiary weapons
Applied an elemental artifact
Killed 15 enemies with the Soldier's action skill
Killed 5 Rakk in under 10 seconds
Rescued a groupmate from death in a co-op game
Killed 25 enemies by ramming them with any vehicle
Completed 15 missions in co-op
Discovered Skag Gully
Earned $1,000,000
Play with at least two other players.
Emerged victorious from an arena match
Completed 5 missions in the Arid Badlands
Killed an enemy plumber-style
Won a duel against another player
Won a duel without taking damage
Earned level 5
Earned level 10