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 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 all missions in Secret Armory
Completed the larger challenge in The Gully coliseum
Completed the lesser challenge in all 3 coliseums
Killed each of the loot midgets
Emerged victorious from an arena match
Killed Crawmerax the Invincible
Reached Level 61
Reached Level 51
Earned level 50
Raced around the Ludicrous Speedway in record time
Destroyed Lance Depot
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
Completed the "Braaaaaaaaaaaaains!" mission
Killed Ned. Again.
Killed Ned...sort of
Completed the "Jakobs Fodder" mission
Completed the "House of the Ned" mission
I bet you never thought you'd be here
Found 25 oil cans
Collected 3 panties, 5 fish in a bag, and 15 pizzas
Collected 15 Claptrap bobbleheads
Completed a crazy request for Tannis
Collected 5 3D glasses
Killed the Interplanetary Ninja Assassin Claptrap
Killed Commandant Steele-trap
Killed Dr. Ned-trap
Found all 6 Claptrap statues
Killed General Knoxx-trap
Defeated the Rakk Hive, the Vault Boss, Sledge, Krom, or Flynt in a co-op game
Play with at least two other players.
Killed an enemy with the Siren's action skill
Killed 15 enemies with the Soldier's action skill
Killed an enemy plumber-style
Killed 5 Rakk in under 10 seconds
Killed 15 enemies with the Berserker's action skill
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
Rescued enough Claptraps to earn 42 inventory slots
Killed 25 enemies with shock weapons
Earned level 40
Killed the Vault Boss
Discovered Eridian Promontory
Completed all missions in the Rust Commons
Discovered Crimson Lance Enclave
Killed Flynt
Earned $1,000,000
Killed 25 enemies with incendiary weapons
Killed the Rakk Hive
Earned level 30
Discovered Trash Coast
Killed Krom
Discovered Krom's Canyon
Reached proficiency level 10 with any weapon type
Discovered The Scrapyard
Sold 50 guns to a shop
Mastered the technology of Pandora
Completed 5 missions in the Rust Commons
Earned level 20
Completed all missions in the Arid Badlands
Killed 25 enemies by ramming them with any vehicle
Equipped a class mod for your character
Killed Sledge
Killed 25 enemies with corrosive weapons
Discovered Headstone Mine
Applied an elemental artifact
Earned level 10
Discovered Sledge's Safe House
Killed 25 enemies with explosive weapons
Killed 15 enemies with the Hunter's action skill
Earned level 5
Discovered Skag Gully
Completed 5 missions in the Arid Badlands