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