With series creator Julian Fellowes hinting that "Downton Abbey" will feature some exciting guest appearances in season 4, we felt compelled to offer some suggestions as to who we'd like to see walking the grounds (or, depending on the character's status, scrubbing the pots). Colin Firth, James Spader and Winona Ryder are just three of the stars we think could bring something compelling to the breakout hit. Keep reading to find out about our other picks. Little fingers crooked, of course.