Which actor played Dr. Watson opposite Benedict Cumberbatch in 'Sherlock'?

Which series follows counterterrorism agent Jack Bauer in real time? Which actor played Jack Bauer in '24'? Which series follows two brothers, one of whom gets himself imprisoned to break the other out? Which Netflix series is set in a women's federal prison? Which series follows Tommy Shelby's gang in 1920s Birmingham, England? Which HBO series follows Atlantic City political boss Nucky Thompson? Which series stars Kevin Spacey as ruthless politician Frank Underwood? Which series stars Kiefer Sutherland as a cabinet member who becomes President after an attack?