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
Obtained Best Weapon by Bladestone
Obtained Best Weapon by Marrowstone
All Rings Obtained
Obtained Best Weapon by Moonlightstone
All Unique Weapons Obtained
Conqueror of Old King Doran
All Spells Learned
Obtained Best Weapon by Faintstone
Obtained Best Weapon by Greystone
Obtained Best Weapon by Sharpstone
Obtained Best Weapon by Dragonstone
All Miracles Learned
Obtained Best Weapon by Cloudstone
Obtained Best Weapon by Mercurystone
Obtained Best Weapon by Darkmoonstone
Obtained Best Weapon by Suckerstone
Obtained Best Bow by Spiderstone
Obtained Best Weapon by Hardstone
Slayer of Demon “Blue Flying Dragon”
Old One Put to Sleep & World United
Slayer of Demon “False King”
Slayer of Demon “Maiden Astraea”
Slayer of Demon “Storm King”
Slayer of Demon “Dirty Colossus”
Slayer of Demon “Leechmonger”
Slayer of Demon “Old Monk”
Slayer of Demon “Maneater”
Obtained Best Weapon by Clearstone
Slayer of Demon “Old Hero”
Slayer of Demon “Penetrator”
Slayer of Demon “Dragon God”
Slayer of Demon “Flamelurker”
Slayer of Demon “Adjudicator”
Slayer of Demon “Fool's Idol”
Slayer of Demon “Armor Spider”
Slayer of Demon “Tower Knight”
Slayer of Demon “Phalanx”