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