The Dead:

The Pilot -- Killed by the Monster
The Polar Bear -- Killed by Sawyer
The Transceiver -- Broken by kate, finished off by Locke
Dharma Initiative Salad Dressing, Ranch Composite -- Destroyed by Michael, assisted by Locke
Enkidu (AKA Yemi -- Eko's Brother) -- Killed by Nigerian Military
Shannon Rutherford -- Killed by Ana Lucia
Boone Carlyle -- Killed in Beachcraft
Steve Jenkins -- Killed by Ethan, assisted by Boone falling asleep (Often confused for Scott whom is alive and well..or wait..maybe it's Scott who's dead..)
Joanna -- Drowned (Ocean current)
Edward Mars (The Marshall) -- Killed by Jack after a failed attempt by Sawyer
Ethan Rom -- Killed by Charlie
Dr. Leslie Arzt -- Blew to bits by dynomite at Black Rock
Dr. Christian Shephard -- Died from Heart attack (Body missing)
Danielle's Team -- Killed by Danielle
Nathan -- Killed by Goodwin
Goodwin -- Killed by Ana Lucia

The Missing:

Walter "Walt" Lloyd -- Taken by The Others
Desmond -- Ran away
Cindy -- Assumed to be taken by The Others
Michael Dawson -- Ran away to find Walt (Possibly taken by The Others)
Kelvin -- Ran away
Dr. Christian Shephard -- Dead body missing from coffin in Caves
Alex Rousseau -- Unknown -- Saved Clare from Ethan and The Others

As Good As Dead
Henry Gale -- 99 percent chance he is one of the others