Trophies - Successfully complete one of the following tasks to get a trophy:

Paid in Fyrestone (Bronze): Completed 5 missions in the Arid Badlands.
Made in Fyrestone (Bronze): Completed all missions in the Arid Badlands.
Paid in New Haven (Bronze): Complete 5 missions in the Rust Commons.
Made in New Haven (Bronze): Completed all missions in the Rust Commons.
My Brother is an Italian Plumber (Bronze): Killed an enemy plumber-style.
Speedy McSpeederton (Bronze): Raced around the Ludicrous Speedway in record time.
You call this archaeology? (Bronze): Applied an elemental artifact.
Ding! Newbie (Bronze): Earned level 5.
Ding! Novice (Bronze): Earned level 10.
Ding! Expert (Bronze): Earned level 20.
Ding! Hardcore (Bronze): Earned level 30.
Ding! Sleepless (Bronze): Earned level 40.
Ding! Champion (Bronze): Earned level 50.
Discovered Skag Gully (Bronze): Discovered Skag Gully.
Discovered Sledge's Safe House (Bronze): Discovered Sledge's Safe House.
Discovered Headstone Mine (Bronze): Discovered Headstone Mine.
Discovered Trash Coast (Bronze): Discovered Trash Coast.
Discovered The Scrapyard (Bronze): Discovered The Scrapyard.
Discovered Krom's Canyon (Bronze): Discovered Krom's Canyon.
Discovered Crimson Lance Enclave (Bronze): Discovered Crimson Lance Enclave.
Discovered Eridian Promontory (Bronze): Discovered Eridian Promontory.
Get A Little Blood on the Tires (Bronze): Killed 25 enemies by ramming them with any vehicle.
Rootinest, Tootinest, Shootinest (Bronze): Killed 5 Rakk in under 10 seconds.
Fence (Bronze): Sold 50 guns to a shop.
Can't We Get BEYOND Thunderdome? (Bronze): Emerged victorious from an arena match.
Duel-icious (Bronze): Won a duel against another player.
Group LF Header (Bronze): Rescued a groupmate from death in a co-op game.
There's No "I" In "Team" (Bronze): Completed 15 missions in co-op.
Weapon Afficiondo (Bronze): Reached proficiency level 10 with any weapon type.
Facemelter (Bronze): Killed 25 enemies with corrosive weapons.
1.21 Gigwatts (Bronze): Killed 25 Enemies with shock weapons.
Pyro (Bronze): Killed 25 enemies with incendiary weapons.
Master Exploder (Bronze): Killed 25 enemies with explosive weapons.
There are some who call me...Tim (Bronze): Equipped a class mod for your character.
Fully Loaded (Bronze): Rescued enough Claptraps to earn 42 inventory slots.
Truly Outrageous (Bronze): Killed an enemy with the Siren's action skill.
Careful, He Bites (Bronze): Killed 15 enemies with the Hunter's action skill.
Reckless Abandon (Bronze): Killed 15 enemies with the Berserker's action skill.
Down in Front! (Bronze): Killed 15 enemies with the Soldier's action skill.
Pandora-dog Millionaire (Silver): Earned $1,000,000.
And They'll Tell Two Friends (Silver): Played in a co-op game with either an employee of Gearbox or someone who had this trophy.
Duelinator (Silver): Won a duel without taking damage.
Borderland Defender (Platinum): You have defeated all bosses and are a powerful force to be reckoned with.

Additionally, there are seven secret trophies:

Secret trophy (Unknown): Unknown.
Secret trophy (Unknown): Unknown.
Secret trophy (Unknown): Unknown.
Secret trophy (Unknown): Unknown.
Secret trophy (Unknown): Unknown.
Secret trophy (Unknown): Unknown.
Secret trophy (Unknown): Unknown.