Go for Quality security Camera

First Decide what you want to achieve. Then decide the location where you will be fitting the camera.

Following are important factors to consider when you are choosing a camera.

Whether it uses high-quality CCD & high quality lens?
Cheaper cameras have fixed lenses- both fixed 'zoom' and fixed focus.
Whether it comes with sufficient cable length?

It should have night vision with auto switching facility. This is very important.