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.
Secure Tohru Adachi
Max out 10 Social Links
Rescue Nanako Dojima
Go to 3 movies at 30 Frame
Finish Aiya's special dish
Max out all social qualities
Rescue Naoto Shirogane
Fight a battle in costume
Max out a Social Link
Enter a special relationship with someone
Secure Mitsuo Kubo
Defeat The Reaper
Deal over 999 damage in 1 attack
Perform 50 All-Out Attacks
Experience a fusion accident
Rank #1 in your class on an exam
Buy 5 things from Tanaka's Amazing Commodities
Rescue Rise Kujikawa
Buy a Persona from the Compendium
Rescue Kanji Tatsumi
Exploit enemy weaknesses 100 times
Buy an item from the Capsule Machine
Rescue Yukiko Amagi
Register a Skill Card
Defeat a Golden Hand
Enter a battle with Player Advantage
Obtain the Persona Izanagi
Earn all trophies
Rescue Marie
Defeat Izanami
Perform 50 Persona fusions
Use 4 or more Personas in a special fusion
Register 100 Skill Cards
Switch Personas 5 times in 1 battle
Hear 250 of Rise's navigation lines
Get 50 Sweep Bonuses
Defeat Margaret
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
Register over 50% of the Compendium
Complete the Persona Compendium
Catch the Sea Guardian
Max out all Social Links
Drink the coffee at Chagall Cafe
Swing the net with perfect timing
Visit Nanako in the hospital 3 times
Win the Miracle Quiz Finals