Who played Frank Reynolds in 'It's Always Sunny in Philadelphia'?

In which TV series is Michael Scofield a main character? Who played Charlie Kelly in 'It's Always Sunny in Philadelphia'? Who played Dennis Reynolds in 'It's Always Sunny in Philadelphia'? In which TV series is Dennis Reynolds a main character? In which TV series is Frank Reynolds a main character? Who played Nancy Botwin in 'Weeds'? In which TV series is Nancy Botwin a main character? Who played Dexter Morgan in 'Dexter'?