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