Full list of all 41 Dark Souls achievements worth 1,000 gamerscore. It takes around 80-100 hours to unlock all of the achievements on Xbox 360.
Discover Blade of the Darkmoon covenant.
Discover Forest Hunter covenant.
Discover Darkwraith covenant.
Acquire best weapon through lightning reinforcement.
Light bonfire flame.
Acquire Estus Flask.
Arrive in Lordran.
Defeat Dark Sun Gwyndolin, the Darkmoon God.
All achievements completed. Congratulations!
Acquire all rare weapons.
Acquire all miracles.
Acquire all pyromancies.
Reach "The Dark Lord" ending.
Acquire best weapon through occult reinforcement.
Acquire best weapon through chaos reinforcement.
Acquire best weapon through divine reinforcement.
Acquire best weapon through enchanted reinforcement.
Acquire best weapon through raw reinforcement.
Acquire best weapon through crystal reinforcement.
Acquire best weapon through fire reinforcement.
Acquire best weapon through magic reinforcement.
Acquire all sorceries.
Discover Warrior of Sunlight covenant.
Acquire best weapon through standard reinforcement.
Reach "To Link the Fire" ending.
Defeat the Four Kings, inheritors of souls.
Defeat the Soul Lord Bed of Chaos.
Defeat Seath the Scaleless, inheritors of souls.
Discover Gravelord Servant covenant.
Defeat the Soul Lord Gravelord Nito.
Defeat Crossbreed Priscilla, the Lifehunter.
Acquire the Rite of Kindling.
Discover Princess's Guard covenant.
Acquire the Lordvessel.
Arrive in Anor Londo.
Acquire the Art of Abysswalking.
Discover Path of the Dragon covenant.
Discover Chaos Servant covenant.
Ring Bell of Awakening in Quelaag's domain.
Discover Way of White covenant.
Ring Bell of Awakening at Undead Church.