Here is the full list of all 50 Persona 4 Golden achievements. It takes around 150-200 hours to unlock all of the achievements on Windows.
Register 100 Skill Cards
Finish Aiya's special dish
Experience a fusion accident
Catch the Sea Guardian
Swing the net with perfect timing
Buy 5 things from Tanaka's Amazing Commodities
Buy an item from the Capsule Machine
Defeat Izanami
Get 50 Sweep Bonuses
Register over 50% of the Compendium
Rescue Marie
Perform 50 Persona fusions
Use 4 or more Personas in a special fusion
Secure Tohru Adachi
Deal over 999 damage in 1 attack
Max out 10 Social Links
Drink the coffee at Chagall Cafe
Rescue Nanako Dojima
Go to 3 movies at 30 Frame
Max out all social qualities
Rescue Naoto Shirogane
Secure Mitsuo Kubo
Enter a special relationship with someone
Rank #1 in your class on an exam
Max out a Social Link
Rescue Rise Kujikawa
Rescue Kanji Tatsumi
Buy a Persona from the Compendium
Defeat a Golden Hand
Exploit enemy weaknesses 100 times
Perform 50 All-Out Attacks
Rescue Yukiko Amagi
Switch Personas 5 times in 1 battle
Fight a battle in costume
Enter a battle with Player Advantage
Register a Skill Card
Obtain the Persona Izanagi
Earn all trophies
Hear 250 of Rise's navigation lines
Defeat Margaret
Defeat The Reaper
Read all books
Win a prize from the vending machine
Buy a special croquette from Sozai Daigaku
Make 5 perfect boxed lunches
Create Izanagi-no-Okami
Complete the Persona Compendium
Max out all Social Links
Visit Nanako in the hospital 3 times
Win the Miracle Quiz Finals