Alien Mist

This is one of my more extreme filters, and works best on images that are brightly-coloured and have plenty of contrast.

This picture of the very lovely Ms Christina Aguilera works well. The filter gives a sort of coloured mist over the darker areas of the image, like this...
Of course, it could be argued that anything that obscures parts of Ms Aguilera is a very bad thing. In view of this, you might prefer to use it only on less photogenic subjects.
The filter dialog has two sliders - just tweak to taste!