In which TV series is Mark Greene a main character?

Who played Phoebe Buffay in 'Friends'? Who played Joey Tribbiani in 'Friends'? In which TV series is Joey Tribbiani a main character? Who played Mark Greene in 'ER'? Who played John Carter in 'ER'? Who played Ray Barone in 'Everybody Loves Raymond'? Who played Debra Barone in 'Everybody Loves Raymond'? In which TV series is Debra Barone a main character?