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