Here is the full list of all 40 LEGO The Hobbit trophies - there are 27 bronze, 8 silver, 4 gold and 1 platinum.
Collect every trophy
Forge all the Perfect Mithril Treasure Items. (Single Player Only)
Play a level in co-op
Use every Dwarf from Thorin's Company in a Buddy-Up attack
Achieve 100% completion
Complete all the quests in Middle-earth. (Single Player Only)
Collect all characters. (Single Player Only)
Forge all the Mithril Treasure Items. (Single Player Only)
Collect 10,000,000,000 studs. (Single Player Only)
Collect all Minikits. (Single Player Only)
Collect all Mithril Bricks. (Single Player Only)
Collect all Treasure Items in levels. (Single Player Only)
Obtain all Master Burglar titles. (Single Player Only)
Use Gandalf's startle ability to dazzle 50 enemies
Collect all Schematics. (Single Player Only)
Use 50 Buddy-Up attacks
Equip yourself with Dazzle Wig, Mithril Rhythm Stick and Mithril Dance Boots.
Equip Thorin with the Mithril Mushroom Crown
Complete the mining game perfectly 50 times
Create a custom character.
Transform to Beorn's bear form.
Complete the Bonus Level
Obtain 150,000 studs from Instruction Builds bonuses. (Single Player Only)
Complete ''Inside Information''
Complete ''On the Doorstep''
Complete ''The Necromancer''
Complete ''Looking for Proof''
Complete ''A Warm Welcome''
Complete ''Barrels Out of Bond''
Complete ''Flies and Spiders''
Complete ''Queer Lodgings''
Complete ''Out of the Frying Pan…''
Complete ''Goblin Town''
Complete ''Over Hill and Under Hill''
Complete ''The Troll Hoard''
Complete ''Roast Mutton''
Complete ''Azog the Defiler''
Collect 99 of any loot
Complete ''An Unexpected Party''
Complete ''Greatest Kingdom in Middle-earth''