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