Torchwood: Sleeper
A scary premise for the bad guys, the characters acting like they know what they're doing, the Gwen/Ianto arm hooking thing (that was so sweet) and the sad and open ending. I liked this episode too, go figure!
But I have a funny feeling about poor Ianto - why, you ask?
First, they establish that Jack and Ianto are officially dating, then they make him snarky and amusing, and not as much a wet blanket as he was last season (from my point of view, anyways)
He's going to be dead by the end of the season, ain't he? RTD and his Joss affliction, means that happy characters and relationships die an horrible, terrible death...or get thrown into an alternative dimension, you pick.