what makes a good opening sequence?

This is one of my favourite opening sequences, it is straight to the point and has a unique and original take on the codes and conventions of the genre. The lighting and general colour scheme of the sequence matches the the tone of the film and what is happening as well as connoting imagery of what might happen later on in the narrative. The best aspect of the sequence for me is the choice in music, the relaxed, cofortable melody contrasts the enigma completely leading the audience to not quite trust what is happening, gives and omonous feel. This opening is a short story within itself, its not too long and dragged out, its fast paced and it allows the viewer to follow and finish a narrative thats not dificult to understand.