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