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