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.
Gunzerked continuously for 90 seconds
Won the most challenging round in Murderlin's Temple
Demonstrated your skill, or lack thereof, at rolling the magical treasure orb of many sides
Vanquished the Ancient Dragons of Destruction
Got an item from Michael Mamaril
Showed thine worst enemy, the abomination known as "The Darkness," who is the nerdiest of them all
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
Allowed a Goliath to level up four times before killing him
Completed all Campaign of Carnage side missions
Completed the mission "Long Way To The Top"
Killed a Chubby
Phaselocked 100 enemies
Completed all Pirate's Booty side missions
Completed all Hammerlock's Hunt side missions
Opened the chest at the bus stop in Fyrestone
I can't even capture it on my camera
Completed the mission "Rising Action"
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 all side missions
Discovered all named locations in Hammerlock's Hunt
Completed the mission "The Fall of Nakayama"
Killed Donkey Mong
Killed a flying enemy with a thrown Tediore weapon
Discovered all named locations in Oasis and the surrounding Pirate's Booty zones
Completed the mission "X Marks the Spot"
Slew Mister Boney Pants Guy
Completed Round 5 of any Circle of Slaughter
Remained in Zero's Deception mode for ten seconds straight
Completed 20 side missions
Defeated Terramorphous the Invincible
Had Purple-rated gear or better equipped in every slot
Completed the mission "My First Gun"
Defeated Jack
Completed the mission "Data Mining"
Completed the mission "Toil And Trouble"
Redeemed 25 tokens
Tipped Moxxi $10,000
Completed the mission "Where Angels Fear To Tread"
Completed the mission "The Man Who Would Be Jack"
Killed a Constructor without it ever building another bot
Completed the mission "The Once and Future Slab"
Completed the mission "Shoot This Guy in the Face"
Completed the mission "Wildlife Preservation"
Completed the mission "Bright Lights, Flying City"
Completed the mission "A Train To Catch"
Collected 10 pictures of Moxxi in Campaign of Carnage
Killed 100 enemies with the Sabre turret
Completed level 1 of all non-level-specific challenges with a single character
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
Reached level 25
Reached level 50
Purchased 5 items from the black market
Completed the mission "A Dam Fine Rescue"
Revived someone from "Fight for Your Life!" that is on your friends list
Reached level 5
Reached level 10
Unlocked 10 customization items
Wielded the Mysterious Amulet
Gave Claptrap a high five
Activated the Backburner's firewall.
Defeated Haderax the Invincible.
Allow Tiny Tina to arm the moonshot cannon.
Defeat the Dark Web.
Equip effervescent-quality gear in all slots (except class mod).
Complete the mission "Paradise Found".