In which TV series is Susan Mayer a main character?

In which TV series is John Locke a main character? Who played Sawyer in 'Lost'? In which TV series is Sawyer a main character? Who played Susan Mayer in 'Desperate Housewives'? Who played Bree Van de Kamp in 'Desperate Housewives'? In which TV series is Bree Van de Kamp a main character? Who played Gabrielle Solis in 'Desperate Housewives'? Who played Lynette Scavo in 'Desperate Housewives'?