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