Lighting
I spent last weekend in Manchester, for the PHP North West conference. While the event itself was located in the Mecure Hotel, the organisers had sorted out a discount with the Britannia, across the road, so many of us were staying there.
It's a traditional hotel, with large balconied staircases running up the middle and felt very reminiscent of a 70s horror movies, or maybe Max Payne.
Even more exciting then, I found that the light in the corridor outside my room was flickering on and off, only adding to the atmosphere.
For this reason, I was actually quite disappointed when I returned to my room on the second night to find they had actually fixed the light. It ruined the feeling that I had somehow travelled back in time to a spooky hotel :(.