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