Trying to think which ones to pick, but here goes:

http://tellshannon815.livejournal.com/3003.html - "Nightmares", with various characters reflecting on the nightmares that haunt their sleep.

http://tellshannon815.livejournal.com/3916.html - "The Man From Dharma", how Ben became the leader of the Others and why he was taken prisoner.

http://tellshannon815.livejournal.com/3595.html - "Grace", more Others featuring background into the fertility problems and island life pre-815, Ethan and his wife in particular.

http://tellshannon815.livejournal.com/2580.html - "Not My Father", Walt's troubled relationship with Michael.

http://tellshannon815.livejournal.com/6663.html - "last Night I Watched You Sleeping", where Penny and Nadia have their men back but must deal with the demons they keep hidden inside.

In fact I'd post more but ought to limit myself to 5, anyone who wants is more than welcome to go read my journal though.