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.
Play with at least two other players.
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
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
Mastered the technology of Pandora
Completed all missions in Secret Armory
Killed each of the loot midgets
Paid for a worthless tour of the world's largest bullet
Killed Crawmerax the Invincible
Destroyed a Lancer while in a Racer
Destroyed Lance Depot
Rescued Athena
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
Killed an enemy with the Siren's action skill
Killed 15 enemies with the Berserker's action skill
Killed 15 enemies with the Hunter's action skill
Completed all missions in the Rust Commons
Earned $1,000,000
Killed the Vault Boss
Discovered Eridian Promontory
Discovered Crimson Lance Enclave
Rescued enough Claptraps to earn 42 inventory slots
Killed Flynt
Killed the Rakk Hive
Discovered Trash Coast
Killed Krom
Discovered Krom's Canyon
Raced around the Ludicrous Speedway in record time
Killed an enemy plumber-style
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 with corrosive weapons
Applied an elemental artifact
Completed all missions in the Arid Badlands
Reached Level 61
Killed 5 Rakk in under 10 seconds
Equipped a class mod for your character
Killed Sledge
Defeated the Rakk Hive, the Vault Boss, Sledge, Krom, or Flynt in a co-op game
Discovered Headstone Mine
Discovered Sledge's Safe House
Killed 25 enemies by ramming them with any vehicle
Reached Level 51
Earned level 50
Earned level 40
Earned level 30
Completed the larger challenge in The Angelic Ruins coliseum
Completed each of the larger challenges in all 3 coliseums
Killed 25 enemies with shock weapons
Emerged victorious from an arena match
Completed the larger challenge in the Hell-Burbia coliseum
Completed the larger challenge in The Gully coliseum
Killed 15 enemies with the Soldier's action skill
Completed the lesser challenge in all 3 coliseums
Won a duel against another player
Won a duel without taking damage
Killed 25 enemies with explosive weapons
Rescued a groupmate from death in a co-op game
Killed 25 enemies with incendiary weapons
Completed 15 missions in co-op
Discovered Skag Gully
Completed 5 missions in the Arid Badlands
Earned level 5
Earned level 10
Earned level 20
Reached proficiency level 10 with any weapon type