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
I can't even capture it on my camera
Killed 100 enemies with the Sabre turret
Phaselocked 100 enemies
Had Purple-rated gear or better equipped in every slot
Completed the mission "A Train To Catch"
Completed the mission "A Dam Fine Rescue"
Completed the mission "My First Gun"
Completed Round 5 of any Circle of Slaughter
Purchased 5 items from the black market
Showed thine worst enemy, the abomination known as "The Darkness," who is the nerdiest of them all
Killed a Chubby
Completed the mission "Bright Lights, Flying City"
Reached level 5
Reached level 10
Reached level 25
Reached level 50
Tipped Moxxi $10,000
Completed 20 side missions
Killed a Constructor without it ever building another bot
Revived someone from "Fight for Your Life!" that is on your friends list
Completed the mission "Rising Action"
Redeemed 25 tokens
Unlocked 10 customization items
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
Hidden
Complete level 1 of all non-level-specific challenges with a single character
Allow a Goliath to level up four times before killing him
Gunzerk continuously for 90 seconds
Get an item from Michael Mamaril
Kill Donkey Mong
Remain in Zero's Deception mode for ten seconds straight
Give Claptrap a high five
Complete all side missions
Complete the mission "X Marks the Spot"
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 all Campaign of Carnage 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
Slay Mister Boney Pants Guy
Introduce thyself to the White Knight
Complete thy quest by rescuing yonder queen
Feed thy noble queen 3 times during one visit to her quarters
Unsheath 5 swords from Immortal Skeletaurs without leaving the area
Win the most challenging round in Murderlin's Temple
Wield the Mysterious Amulet
Demonstrate your skill, or lack thereof, at rolling the magical treasure orb of many sides
Vanquish the Ancient Dragons of Destruction
Defeated Haderax the Invincible.
Defeated the Dark Web.
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).