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