Reiser's Burke from Aliens was the ultimate depiction of a greedy eighties yuppie. He literally killed it in that role. What was frightening was how easily one could imagine meeting this guy for cocktails after work on Wall Street and then having him stab you in the back with no remorse. He was the ultimate psycho in that film. The character reminds me of Paul Bernardo, a vicious killer from Ontario, Canada.
What was particularly brilliantly executed by Burke was that as a complete sociopath, he did not see himself as evil. He was completely internally oblivious to the terrible things he was doing because of his materialistic, greedy outlook. We encounter people like this in real life, and until they cross that line, we tolerate them, and more often then not, we revere them as captains of industry. It was such a great statement on humanity and played so well by Reiser. He was the Perfect Organism that Ash spoke of when he said "no conscience, no delusions of morality". Just a simple, low-life, animal, disguised as a human being.