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