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