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