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