My favorite new characters from season 4 of LOST.

Daniel and Charlotte
Daniel would be my #1 favorite new character of season 4. When he was introduced, he seemed friendly enough, but being with the freighters, there was still a question of trust. After seeing his wonder of being on the Island and his understanding of how special a place it was, his sweetness, and his geeky nerdiness, put me on his side quickly. I was probably trusting him by The Other Woman, when he neutralized the poison gas at the Tempest. The way he is tied into the mythology is tragic but interesting, from his parents, to his time traveling, to his death by the hand of his own mother.

Charlotte gets my # 4 slot. I loved her introduction, from the Tunisian Desert to the landing in the lake on Island and being found by the barracks group of Losties. But I think her character was brought on to be killed by the time traveling which made TPTB not really seem to invest in developing her character. But I did enjoy her scenes and felt really bad when she died.

Miles and Frank
These 2 are almost tie in my book, but Miles edges out Frank cause he didn't declare himself a Yankees fan. Miles, my #2 favorite of season 4, has a sarcastic edge which I enjoy. His ability to talk to ghosts makes him awesome and his scenes with Hurley are wonderful. Nana was mentioning how Hurley and Charlie were great together, that has been missing. But Miles, who is totally different from Charlie, can fill that void nicely. Miles was the only voice of intelligence and reason during the Incident also. It was quick, but I loved him helping to rescue his father, and he was the only one who was brave enough to ask out loud if anyone actually thought Jack's plan may cause what they are trying to prevent and maybe it would have been better to do nothing. Miles being Pierre Chang's son is a great tie in for his character too.

Frank is just awesome and cool, so he gets #3. He is still around, brought back to the Island by Ajira 316. Even though he wasn't on Oceanic 815, the Island did get him there with the freighter group initially. He went between groups in season 5, ending up with Ilana and crew. I have a feeling TPTB are just keeping him around to have a character we've invested in die, but I am hoping for better.

Matthew Abaddon
Honorable mention goes to Abaddon. His mysterious introduction talking to Hurley and his untimely death while helping Locke makes him a memorable character. His intentions still seem ambiguous to me, he was ultimately working for Widmore, and I am still torn about Widmore. Abaddon was killed off too early and he is awesome on Fringe, but again, I digress.
Thus the countdown continues...