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