I have indeed been watching The Shadow Line, EC, but last show I nearly had hysterics as it went off into high camp/spoofland with not just Stephen Rea doing Quietly Menacing Evil, but Anthony Sher (I still see him as the horrifically hunched Richard III on crutches, lurching about the stage) also going for QME, and Rafe Spall slightly overdoing the "Me, I'm Mad, Me" Staring With Quietly Menacing Evil. Come on, lads, how much Quietly Menacing Evil can one take in one series? Leave a bit over for the next one!
As for Luther, I'm a huge Idris Elba fan, and pined pathetically when he was bumped off, along with 99.5% of the cast, in The Wire: the only sharp-dressed man, and he gets the boom-boom treatment. No justice! And then later found out he's not American at all, but from good ole Lunnun town - terrific accent work there, totally believable.