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