Who played Josh Lyman in 'The West Wing'?

In which TV series is Christopher Moltisanti a main character? In which TV series is Josiah Bartlet a main character? Who played C.J. Cregg in 'The West Wing'? In which TV series is C.J. Cregg a main character? In which TV series is Hal a main character? Who played Malcolm in 'Malcolm in the Middle'? Who played Lois in 'Malcolm in the Middle'? Who played Lorelai Gilmore in 'Gilmore Girls'?