In which TV series is Rick Grimes a main character?

Who played Damon Salvatore in 'The Vampire Diaries'? In which TV series is Damon Salvatore a main character? Who played Richard Castle in 'Castle'? Who played Rick Grimes in 'The Walking Dead'? Who played Daryl Dixon in 'The Walking Dead'? In which TV series is Daryl Dixon a main character? Who played Negan in 'The Walking Dead'? In which TV series is Negan a main character?