This page includes a list of the main characters in the tv show along with some information about them. The information included only goes to the end of the third season.
Characters (page 3)

Danielle Rousseau, played by Mira Furlan, is a woman that has lived on the island for sixteen years.  She had been part of a scientific research team traveling around in a ship.  One day, they heard the numbers being repeated over their radio and went to investigate.  Their ship crashed and they had to survive on the island.  Danielle said that the rest of her team got sick a few months after they arrived and that she killed them all.  Her baby daughter Alex was then taken from her by the Others and she spent the next sixteen years alone and searching for her.  When Sayid got caught in one of her traps, she took him to her hideout and tortured him, thinking that he was one of Them.  He repaired her music box for her and she came to trust him.  Many of the people on the island believed that Danielle was crazy (she kidnapped Claire's baby, tortured Sayid, stalks around the jungle carrying a rifle...), but she was simply a mother who lost her child and would do anything to get her back.  After sixteen years of waiting, Danielle was finally reunited with her baby girl in the third season finale.

Henry Ian Cusick is Desmond Hume, who first appeared in the second season of Lost.  He was in love with a woman named Penelope, but her father did not approve of their relationship, so he went on a trip around the world in a sailboat to prove himself and regain his honor.  He crashed on the island, was found by Kelvin Inman, and was taken to the hatch.  He had been living in the hatch for three years before Locke blew it open.  When the computer was shot, he took off - trying to get as far away from the hatch as he could - and was not seen again until weeks later when he happened upon the Losties beach in his sailboat.  No matter how hard he tried, he couldn't get away from the island, and he ended up back in the hatch with Locke to find out what happened when the button wasn't pushed.  Minutes before the timer ran out, Desmond realized that the last time the counter went past zero was the day that the plane crash occurred.  He tried to explain the importance of pushing the button, but Locke wouldn't hear it.  He ended up going down to initiate the fail-safe, possibly sacrificing himself for the safety of the world.  Once out of the hatch, Desmond found that he had the power to see into the future, mainly flashes of Charlie's death.  He tried his hardest to save Charlie each time he saw a flash, but Charlie took his fate into his own hands in the end and sacrificed himself.  The two had become very close because of their connection, and Desmond will most likely take this very hard and place all of the blame on himself for a long while.  Great, just one more thing for him to regret in his life.  Can't the guy ever get a break?

Former cop Ana Lucia Cortez was played by Michelle Rodriguez.  She was shot on duty one night and lost the child she was carrying.  Ana then avenged the death of her baby by killing the man who shot her in cold blood.  Her mother, the police chief knew that she did this and wanted to help Ana.  Ana Lucia was still distraught though and decided that she would rather quit the police force.  She took a job at a security checkpoint at the airport and met Jack's father in the airport bar one evening.  He invited Ana to accompany him to Australia and be his bodyguard for the trip.  She agreed and both wallowed in their sorrows and alcohol for awhile.  She met Jack in the airport bar in Australia on her way back to LA and he said that they would have to have a drink together on the plane.  It didn't work out, however, because Ana was in the tail section of the plane that broke off.  She took on a leadership role among the tailies and tried to protect them as best as she could.  The Others were relentless with their group though, and she was very wary about new people.  It was her idea to cage Michael, Jin, and Sawyer when they washed up on their beach and also to go to the other side of the island.  When she heard whispers in the jungle, she shot blindly towards the source and ended up killing Shannon.  She felt awful and kind of snapped at that moment.  She was already hard headed and trigger happy, but she was a bit off since that incident.  She exiled herself from the group because of her mistake, but Jack tried his hardest to keep her in the loop.  Ana tried to kill Henry Gale because of the anguish that the Others caused her and her group, but couldn't fire the gun.  She gave it to Michael becuase he said that he could do it, but he ended up turning the gun on her and shooting her in the chest.

Libby, a clinical psychologist and former mental patient, was played by Cynthia Watros.  She was in the tail section of the plane and worried a lot about Ana during their time together.  She trusted Ana to keep her and the other tailies alive, but did not agree with a lot of her methods of doing so (such as throwing Nathan in the pit or tying Sayid to a tree after she shot Shannon).  Once they were reunited with the rest of the survivors, Libby kind of latched on to Hurley.  He thought that he knew her from somewhere and she told him that he stepped on her foot when he was boarding the plane.  Libby was lying though, Hurley recognized her from the mental hospital that they both were in.  We never learned much about Libby's past other than that and that she gave Desmond her late husband's boat so that he could participate in his boat race.  Libby was so nice to Hurley and helped him overcome his food addiction, and she began to fall for him as he fell for her.  They were going to go on a picnic for their first date, and Libby went to the hatch to get a blanket.  It was the complete wrong time to do so though, as Michael shot her in the gut right after he shot Ana.  Libby was not as lucky as Ana though because she did not die right away.  There was nothing that Jack could do except make her last moments comfortable.  Hurley was heartbroken and believed that it was his fault for forgetting the blankets.  Libby's tried to warn them about Michael with her last words, but wasn't able to get her point across before she died.

Adewale Akinnuoye-Agbaje played the strong and silent Mr. Eko.  Mr. Eko was one of the survivors from the tail section of the plane and was instrumental in getting his group to the other side of the island.  When he was younger, some men came to his villiage in Nigeria and tried to force his brother Yemi to kill a man.  Yemi hesitated and Eko took the gun to save his brother.  He was brought up with these bad men and became a warlord and drug runner of sorts while Yemi became a priest.  He forced his brother to make him and his men priests as well so that they could smuggle a plane-load of Virgin Mary statues filled with heroine out of the country.  Yemi tried to lead Eko back onto the right path and was killed in the process.  Eko took his brother's place in the church and began to follow God once again.  When the Others came to the tailies beach, Eko ended up killing two of them and refused to speak for a long time.  He took to sitting alone and carving scripture into his "Jesus Stick" as it was named by Charlie.  Even after he began to speak again, he only did so when it was necessary.  He was a very religious man and wanted to help everyone else find their way - he even began to build a church on the island.  When he saw that Charlie had one of the Virgin Mary statues, Eko forced him to bring him to the plane where he found it, and Eko was finally able to say goodbye to his brother.  When Locke lost his faith in the island, Eko tried to help him and even took over pushing the button because he knew that it was important.  Sadly, Mr. Eko was killed by the smoke monster in the beginning of season 3, but he did help restore Locke's faith in the process.

Kiele Sanchez and Rodrigo Santoro played Nikki and Paolo, two promoted red-shirts who never really fit in at all and were thus killed off.  They just popped up in the beginning of the third season as if they had been their the whole time and it all felt very wrong.  Nikki and Paolo had just pulled off a large diamond heist before they crashed on the island and spent a large amount of their time trying to find the bag with the diamonds in it.  They found the Pearl station and the plane in which Boone died before anyone else in their search.  Nikki was obsessed with finding the bag and Paolo began to feel as if she cared about the diamonds more than him or their relationship.  He eventually found them (and his nicotine gum), but didn't tell Nikki.  Instead, he hid the diamonds in the toilet in the Pearl station.  While he was down there, Paolo overheard Ben and Juliet's plan to get Jack, Kate, and Sawyer, but he didn't tell anyone.  Nikki finally gave up on her search for the diamonds and the two grew close once again, but then she saw that he had his gum and knew that he had found the diamonds.  She decided to get back at Paolo by throwing a spider on him that would paralyze him for about eight hours, during which she would do whatever she wanted to him.  Her plan backfired however, when she was bit and paralyzed as well.  Sawyer, Hurley, and Charlie thought that they were dead and tried to solve the mystery of their deaths, but to no avail.  Eight hours later, Nikki's paralysis began to wear off as Sawyer and Hurley shoveled sand on top of her and Paolo, but it was too late and the two were buried alive.