Liking oneself is a precondition for liking others. Yet to be in love with oneself is at best suspect, at worst a tragic fate condemning the afflicted to a life deprived of true intimacy. Narcissism is a universal psychological phenomenon, with healthy and unhealthy forms. Pathological forms of narcissism may be an attempt to find basic security in the face of environmental difficulty or trauma. Psychological treatment can help lessen the fundamental loneliness of the narcissistic sufferer.
Jeremy Holmes from Freud.org.uk

Most people dismiss Narcissists as amusing, but many of them harm others as they try to maintain their guise of superiority. Brian Blackwell, the 19-year-old who killed his parents and then went on a holiday financed by their credit cards, was diagnosed as suffering from narcissistic personality disorder. Personality disorders expert and consultant forensic psychologist Kerry Daynes, from Manchester, said: "Many psychopaths have narcissistic traits, and you most often see NPD when treating psychopaths.- That is not to say that everyone with NPD is a psychopath, or that every psychopath is narcissistic - but they go together in a lot of cases."

I sometimes think a narcissist is someone who is not human, but who looks human and acts human, an alien from outer-space, or a spoiled child, or a crazy person (crazy like a fox). Some alien race has snatched the humanity from the narcisisst, leaving an empty husk that tries its best to act human. If you make the mistake of thinking they are normal human beings then you will remain their victim. Psychopaths are more dangerous but not as insidious as a narcissist.

Ns are great actors. If you walk into a bar, can you tell who is the social drinker and who is the alcoholic? Narcissists blend in. They range in age and sex and nationality and intelligence; some are more harmful than others, some are even good. They all have DSM IV characteristics.

List of words to describe a Narcissist:

Two words describe them - spoiled child...

Another list of characteristics of NPD

If you know someone who has five or more of the DSM IV characteristics (and barring any differential diagnosis) then you might be dealing with a personality disorder called NPD.

Oh, by the way, we all have some of these characteristics... If you are a full blown narcissist reading this, welcome, you are one of the most incredible people world in the world. Your favorite letters are; M, E and I.

Healthy narcissism is a normal passage which leads to self esteem, ambition and the capacity to form satisfying relationships. As long as you can integrate it into your normal mental health, then it is not a bad thing. Remember, all power corrupts and absolute power corrupts absolutely. Balanced people are normal people.

Detailed definition from The Columbia Electronic Encyclopedia

British boy murders parents, doctors diagnose him with NPD

Here is a warning about internet abusers.