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