3. Life On Mars Meets Downton Abbey
Downton Abbey: A program from ITV (or PBS for any of us Yankees) that centers on the titular Downton Abbey, a fictional country estate, and the lives of those who live there, and how their lives are affected by the events around them (such as the Titanic sinking, World War I, the Spanish Flu, etc).
Life On Mars: A series from BBC One (and its short-lived American adaption on ABC) features Detective Sam Tyler who suffers an accident in 2006, then awakes to find himself in 1973, apparently working on the police force in that era. Frequently the series questions whether Tyler is hallucinating, dreaming, or has actually traveled in time.
The Crossover: This one's a stretch. After the show's fairly satisfying conclusion, have another character from Life On Mars suffer a similar accident and awake in 1917... as a servant in Downton Abbey. No? You really don't think so? Fine, we'll just move on to....