Press Up(2), Down(2), Left, Right, Left, Right, Circle, X, Start at the title screen to unlock the "Extra Wubs" option at the "Gameplay" section of the "Options" menu. Note: Extra Wubs has no effect in the game.
True Vault Hunter mode
Successfully complete Story mode under the Normal difficulty setting.
Have a saved game file from Borderlands to unlock characters skin from the original game.
Place the desired item(s) on a character, and ready or create a second character to take on as many of the item as you wish. Start a two-player co-op game with the first character as player 1 (and the other character as player 2, obviously). Give desired item(s) to player 2 and have player 2 save and leave game. Quit game from PS3 system menu. Because the game doesn't save player 1 when player 2 leaves, nor when you quit from the system menu, now both players have said item(s). Repeat as desired (for faster duplication, transfer all copies of the item to player one, save-and-quit with both, and start over with the duplicates on player 1).
Badass Rank Farming
To build a high Badass Rank, and gain all the perks associated with it, create a pair of new characters in co-op mode and have player 1 beat player 2 in 50 duels. This gives 166 Badass Ranks. Save and quit, then start another new game, creating another new character for player 1 (don't bother messing with player 2's character). Fight another 50 duels, with player 1 winning them all for 166 more Badass Ranks. Repeat as desired, and delete the pile of unwanted characters when you're done.. If you set the controller configuration to something where you can just keep tapping the melee-attack button without ruining your aim at the other player, you can finish a duel-run like this in roughly 10 minutes. Thus, over the course of one hour, you can build up 996 Badass Ranks.
Easy Badass ranks
Create a new character and join the game as a guest on controller two. Stand in front of the guest character with your main character and start a duel. Win the duel and repeat the process. Fifty duel victories will result in a gain of 166 Badass ranks. Create a new character and repeat the process as many times as desired.
Easy money and Eridium
At the beginning of the Southpaw Steam & Power Facility, where you do the "Assassinate The Assassins" mission, is a room of lockers and small boxes. Check all the boxes and lockers, then go to the "Pause" menu. Select "Quit", then "Save And Quit". When the game returns to the title screen, continue your game. You will appear at the begging of Southpaw, and the boxes and lockers will have respawned with new items (weapons, money, ammo, shields, and Eridium). Loot the boxes and lockers again and repeat. The entire process is very fast and you can receive at least one Eridium every four times that the room is cleared. This is a good way to get black market items early in the game.
Go to Sanctuary Hole after Chapter 9. Jump off a cliff then go to Caustic Caverns. Run northwest to Guardian Ruins then go to the minecarts and turn right. Jump over the rectangular rocks then turn left to find Minecraft dirt. Break though it to reach Minecraft stone, cobblestone, and coal. Break though those to find Creepers, as well as blocks of gold, diamond, iridium and more. Kill the Badass Creeper to unlock Minecraft-themed skins (Steve Head, Steve's Clothes etc.).
Arctic Explorer (Bronze)
Objective: Discovered all named locations in Three Horns, Tundra Express, and Frostburn Canyon
Better Than Money (Bronze)
Objective: Purchased 5 items from the black market
Better Than You Were (Bronze)
Objective: Reached level 10
Blight Explorer (Bronze)
Objective: Discovered all named locations in Eridium Blight, Arid Nexus, and Sawtooth Cauldron
Bounty Hunter (Bronze)
Objective: Completed 20 side missions
Build Buster (Bronze)
Objective: Killed a Constructor without it ever building another bot
Cute Loot (Bronze)
Objective: Killed a Chubby
Decked Out (Bronze)
Objective: Had Purple-rated gear or better equipped in every slot
Definitely An Italian Plumber (Bronze)
Objective: Killed Donkey Mong
Friendship Rules (Bronze)
Objective: Revived someone from "Fight for Your Life!" that is on your friends list
Goliath, Meet David (Bronze)
Objective: Allowed a Goliath to level up four times before killing him
High-Flying Hurler (Bronze)
Objective: Killed a flying enemy with a thrown Tediore weapon
Highlands Explorer (Bronze)
Objective: Discovered all named locations in The Highlands, Thousand Cuts, and Wildlife Exploitation Preserve
How Do I Look? (Bronze)
Objective: Unlocked 10 customization items
Not Quite Dead (Bronze)
Objective: Reached level 5
Phased and Confused (Bronze)
Objective: Phaselocked 100 enemies
Sabre Rattler (Bronze)
Objective: Killed 100 enemies with the Sabre turret
So Much Blood! (Bronze)
Objective: Gunzerked continuously for 90 seconds
Sugar Daddy (Bronze)
Objective: Tipped Moxxi $10,000
Token Gesture (Bronze)
Objective: Redeemed 25 tokens
Tribute To A Vault Hunter (Bronze)
Objective: Got an item from Michael Mamaril
Unseen Predator (Bronze)
Objective: Remained in Zero's Deception mode for ten seconds straight
Up High, Down Low (Bronze)
Objective: Gave Claptrap a high five
Urban Explorer (Bronze)
Objective: Discovered all named locations in Sanctuary, Opportunity, and Lynchwood
Went Five Rounds (Bronze)
Objective: Completed Round 5 of any Circle of Slaughter
Always Improving (Silver)
Objective: Reached level 25
Capped Out...For Now (Silver)
Objective: Reached level 50
Did It All (Silver)
Objective: Completed all side missions
World Traveler (Silver)
Objective: Discovered all named locations
Challenge Accepted (Gold)
Objective: Completed level 1 of all non-level-specific challenges with a single character
Borderland Defender Round Two (Platinum)
Objective: Unlocked all Borderlands 2 trophies
A Road Less Traveled (Bronze)
Objective: Completed the mission "The Road To Sanctuary"
An Old Flame (Bronze)
Objective: Completed the mission "Hunting The Firehawk"
Can See My House From Here (Bronze)
Objective: Completed the mission "Bright Lights, Flying City"
Dragon Slayer (Bronze)
Objective: Completed the mission "Best Minion Ever"
Farewell, Old Girl (Bronze)
Objective: Completed the mission "Wildlife Preservation"
Feels Like The First Time (Bronze)
Objective: Opened the chest at the bus stop in Fyrestone
First One's Free (Bronze)
Objective: Completed the mission "My First Gun"
Got The Band Back Together (Bronze)
Objective: Completed the mission "The Once and Future Slab"
New In Town (Bronze)
Objective: Completed the mission "Plan B"
No Man Left Behind (Bronze)
Objective: Completed the mission "A Dam Fine Rescue"
Sky's The Limit (Bronze)
Objective: Completed the mission "Rising Action"
Well That Was Easy (Bronze)
Objective: Completed the mission "Shoot This Guy in the Face"
What does it mean? (Bronze)
Objective: I can't even capture it on my camera
Wilhelm Screamed (Bronze)
Objective: Completed the mission "A Train To Catch"
An Angel's Wish (Silver)
Objective: Completed the mission "Where Angels Fear To Tread"
Bombs Away (Silver)
Objective: Completed the mission "Toil And Trouble"
Identity Theft (Silver)
Objective: Completed the mission "The Man Who Would Be Jack"
Knowing Is Half The Battle (Silver)
Objective: Completed the mission "Data Mining"
Thresher Thrashed (Silver)
Objective: Defeated Terramorphous the Invincible
Cool Story, Bro (Gold)
Objective: Defeated Jack
DLC: Captain Scarlett and Her Pirate's Booty
Objective: Discovered all named locations in Oasis and the surrounding Pirate's Booty areas.
Objective: Completed all Pirate's Booty side missions.
Treasure Hunter (Gold)
Objective: Completed the mission "X Marks the Spot"
DLC: Mr. Torgue's Campaign of Carnage
Objective:Completed the mission "Long Way To The Top"
Objective:Completed all Campaign of Carnage side missions
Objective:Collected 10 pictures of Moxxi in Campaign of Carnage