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