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