Here is the full list of all 51 The Sims 3 trophies - there are 34 bronze, 15 silver, 1 gold and 1 platinum.
Get 5 positive moodlets at the same time on one Sim.
Build a home of at least §350,000 property value on a large lot.
Complete a Lifetime Wish before becoming a Young Adult.
Gain 250,000 Lifetime Happiness on one Sim.
Complete 50 Challenges.
Complete 100 Challenges.
Complete 150 Challenges.
Complete 100 Wishes.
Complete 1,000 Wishes.
Create a household.
Complete the in-game tutorial.
Learn the Charisma Skill.
Complete 10 Wishes.
Use a Karma Power.
Make a best friend.
Attend a town event.
Have a first kiss.
Make Woo Hoo.
Reach level 5 in a career.
Buy a car.
Complete 10 Opportunities.
Experience the Meta.
Explore the catacombs after dark.
Write a book.
Throw an awesome party.
Become a partner of the Paragon Personal Private Charity Warehouse.
Design and save 20 styles using Create a Style.
Get engaged.
Move into a new home.
Reach level 10 in a Skill.
Welcome a child into the family.
Become best friends with your boss and all of your co-workers.
Reach the maximum potential Karma.
Complete a Lifetime Wish.
Raise your household's value to §35,000 or more.
Resurrect a Sim.
Unlock every Good Karma Power by purchasing them with Challenge Points.
Complete any 2 Skill Journal Milestones.
Complete any 10 Skill Journal Milestones.
Gain 150,000 Lifetime Happiness Points on one Sim.
Use the Epic Fail Karma Power on 13 unsuspecting sims not in your family.
Prepare a perfect meal.
Buy out a commercial property in town.
Unlock all other Trophies.
Become a public menace.
Get an insurance check for over §15,000 after using the Firestorm Karma Power.
Grow a perfect plant.
Start 5 romantic relationships.
Go on a date.
Extinguish a Sim on fire.
Catch a perfect fish.