In which TV series is Khadijah James a main character?

Who played Niles Crane in 'Frasier'? In which TV series is Niles Crane a main character? Who played Daphne Moon in 'Frasier'? Who played Khadijah James in 'Living Single'? Who played Monica Geller in 'Friends'? In which TV series is Monica Geller a main character? Who played Phoebe Buffay in 'Friends'? Who played Joey Tribbiani in 'Friends'?