2. Blink
What can really be said about this episode that hasn't been said? It's a fan favourite. It was the Angels debut. They were arguably at their most effective in this episode too. The trailer however, stands out because we didn't know anything about the episode. It wasn't a fan favourite before it aired, but even the trailer hinted at genuine intrigue. It told us almost nothing about the episode, we simply had a few clips of the Doctor staring directly into the camera and insisting that we don't blink. This made up the meat of the trailer, and it worked for two reasons. Firstly the direct adress to the camera really gives the impression that he is talking to us, the audience and David Tennant does a really good job of making us feel just how dangerous it would be if we were to blink. And secondly it doesn't show us much of Sally Sparrow, it focuses on the Doctor's parts, which despite being minimal in the episode itself, are really the selling point going in. We know the Doctor, he's familiar. Sally Sparrow wasn't, and despite proving to be one of the best one of characters, we couldn't know that beforehand. Instead we just got a few clips of her and Lawrence Nightingale looking a bit scared, and combined with the clips of the Doctor it all added up to guarantee our place in front of the telly for the next episode.