I first saw Samaire playing the role of Anna Stern on Season 1 of The OC, as did most other people probably, back in 2003. But unfortunately she left the series, but luckily for her the writers left good probability for a return.
I must admit that after she had left The OC I hadn't seen her on TV and so forgot about her completely, but to her fans pleasure samaire returned in April 2006.
Her storyline involves being at the same college as another character of the show giving hope that she may well have a more permanent role in The OC's season 4.
This is very good as in my opinion we don't see enough of her.