Full list of all 75 Borderlands 2 achievements worth 1,875 gamerscore. It takes around 60-80 hours to unlock all of the achievements in the base game.
The base game contains 69 achievements worth 1,625 Gamerscore, and there is 1 DLC pack containing 6 achievements worth 250 Gamerscore.
Killed a flying enemy with a thrown Tediore weapon
Completed all Campaign of Carnage side missions
Completed the mission "Long Way To The Top"
Defeated Jack
Completed the mission "Data Mining"
Completed the mission "Toil And Trouble"
Completed the mission "Where Angels Fear To Tread"
Completed the mission "The Man Who Would Be Jack"
Completed the mission "The Once and Future Slab"
Phaselocked 100 enemies
Completed the mission "Shoot This Guy in the Face"
Reached level 5
Reached level 10
Reached level 25
Reached level 50
Completed Round 5 of any Circle of Slaughter
Unsheathed 5 swords from Immortal Skeletaurs without leaving the area
Introduced thyself to the White Knight
Killed 100 enemies with the Sabre turret
Completed all Pirate's Booty side missions
Completed the mission "X Marks the Spot"
Discovered all named locations in Oasis and the surrounding Pirate's Booty zones
Won the most challenging round in Murderlin's Temple
Completed thy quest by rescuing yonder queen
Wielded the Mysterious Amulet
Showed thine worst enemy, the abomination known as "The Darkness," who is the nerdiest of them all
Demonstrated your skill, or lack thereof, at rolling the magical treasure orb of many sides
Opened the chest at the bus stop in Fyrestone
Fed thy noble queen 3 times during one visit to her quarters
Discovered all named locations in Sanctuary, Opportunity, and Lynchwood
Discovered all named locations in Three Horns, Tundra Express, and Frostburn Canyon
Discovered all named locations in The Highlands, Thousand Cuts, and Wildlife Exploitation Preserve
Discovered all named locations in Eridium Blight, Arid Nexus, and Sawtooth Cauldron
Completed the mission "Wildlife Preservation"
Revived someone from "Fight for Your Life!" that is on your friends list
Purchased 5 items from the black market
Killed a Chubby
I can't even capture it on my camera
Killed a Constructor without it ever building another bot
Completed the mission "Bright Lights, Flying City"
Completed the mission "Rising Action"
Completed the mission "A Train To Catch"
Got an item from Michael Mamaril
Completed the mission "A Dam Fine Rescue"
Completed the mission "Hunting The Firehawk"
Allowed a Goliath to level up four times before killing him
Slew Mister Boney Pants Guy
Defeated Terramorphous the Invincible
Completed the mission "My First Gun"
Completed the mission "Plan B"
Completed the mission "The Road To Sanctuary"
Completed the mission "Best Minion Ever"
Completed 20 side missions
Gave Claptrap a high five
Tipped Moxxi $10,000
Vanquished the Ancient Dragons of Destruction
Had Purple-rated gear or better equipped in every slot
Redeemed 25 tokens
Unlocked 10 customization items
Complete level 1 of all non-level-specific challenges with a single character
Discover all named locations
Gunzerk continuously for 90 seconds
Kill Donkey Mong
Remain in Zero's Deception mode for ten seconds straight
Complete all side missions
Collect 10 pictures of Moxxi in Campaign of Carnage
Complete the mission "The Fall of Nakayama"
Complete all Hammerlock's Hunt side missions
Discover all named locations in Hammerlock's Hunt
Completed the mission "Paradise Found".
Activated the Backburner's firewall.
Allowed Tiny Tina to arm the moonshot cannon.
Defeated the Dark Web.
Defeat Haderax the Invincible.
Equip effervescent-quality gear in all slots (except class mod).