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