Here is the full list of all 38 Demon's Souls trophies - there are 27 bronze, 5 silver, 5 gold and 1 platinum.
All Trophies Obtained
All Miracles Learned
All Spells Learned
All Unique Weapons Obtained
Obtained Best Weapon by Faintstone
Old One Put to Sleep & World United
Obtained Best Weapon by Dragonstone
Slayer of Demon “Dragon God”
All Rings Obtained
Conqueror of Old King Doran
Slayer of Demon “False King”
Slayer of Demon “Blue Flying Dragon”
Obtained Best Weapon by Bladestone
Obtained Best Weapon by Greystone
Slayer of Demon “Flamelurker”
Obtained Best Weapon by Clearstone
Slayer of Demon “Penetrator”
Obtained Best Weapon by Hardstone
Obtained Best Weapon by Sharpstone
Obtained Best Weapon by Marrowstone
Obtained Best Weapon by Mercurystone
Slayer of Demon “Maiden Astraea”
Obtained Best Bow by Spiderstone
Obtained Best Weapon by Suckerstone
Slayer of Demon “Dirty Colossus”
Obtained Best Weapon by Moonlightstone
Obtained Best Weapon by Cloudstone
Slayer of Demon “Old Monk”
Slayer of Demon “Maneater”
Obtained Best Weapon by Darkmoonstone
Slayer of Demon “Storm King”
Slayer of Demon “Old Hero”
Slayer of Demon “Leechmonger”
Slayer of Demon “Adjudicator”
Slayer of Demon “Fool's Idol”
Slayer of Demon “Armor Spider”
Slayer of Demon “Tower Knight”
Slayer of Demon “Phalanx”