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.
Remained in Zero's Deception mode for ten seconds straight
Discovered all named locations in Eridium Blight, Arid Nexus, and Sawtooth Cauldron
Discovered all named locations in Three Horns, Tundra Express, and Frostburn Canyon
Demonstrated your skill, or lack thereof, at rolling the magical treasure orb of many sides
Vanquished the Ancient Dragons of Destruction
Completed the mission "Bright Lights, Flying City"
Gave Claptrap a high five
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
Slew Mister Boney Pants Guy
Killed Donkey Mong
Completed Round 5 of any Circle of Slaughter
Completed the mission "The Fall of Nakayama"
Collected 10 pictures of Moxxi in Campaign of Carnage
Had Purple-rated gear or better equipped in every slot
Completed the mission "Long Way To The Top"
Completed the mission "X Marks the Spot"
Defeated Jack
Completed the mission "Data Mining"
Opened the chest at the bus stop in Fyrestone
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"
Completed the mission "Shoot This Guy in the Face"
Completed the mission "Wildlife Preservation"
Killed a Constructor without it ever building another bot
Killed a Chubby
Completed the mission "Rising Action"
Completed the mission "A Train To Catch"
Completed the mission "A Dam Fine Rescue"
Unlocked 10 customization items
Redeemed 25 tokens
Purchased 5 items from the black market
Completed 20 side missions
Completed the mission "Hunting The Firehawk"
Defeated Terramorphous the Invincible
Discovered all named locations in Sanctuary, Opportunity, and Lynchwood
Discovered all named locations in The Highlands, Thousand Cuts, and Wildlife Exploitation Preserve
Reached level 10
Reached level 25
Reached level 50
Completed the mission "Plan B"
Completed the mission "The Road To Sanctuary"
Completed the mission "Best Minion Ever"
Reached level 5
Revived someone from "Fight for Your Life!" that is on your friends list
Completed the mission "My First Gun"
Complete level 1 of all non-level-specific challenges with a single character
Allow a Goliath to level up four times before killing him
Discover all named locations
Tip Moxxi $10,000
Kill 100 enemies with the Sabre turret
Phaselock 100 enemies
Gunzerk continuously for 90 seconds
Get an item from Michael Mamaril
Kill a flying enemy with a thrown Tediore weapon
Hidden
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 all Campaign of Carnage side missions
Complete all Hammerlock's Hunt side missions
Discover all named locations in Hammerlock's Hunt
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
Allowed Tiny Tina to arm the moonshot cannon.
Completed the mission "Paradise Found".
Activated the Backburner's firewall.
Defeat Haderax the Invincible.
Defeat the Dark Web.
Equip effervescent-quality gear in all slots (except class mod).