Really, I'm for either, as long as they are in their pure forms. It seems that we have somewhat of a tainted view of both, though Communism seems to have departed most from it's true values. Communism and Capitalism are founded on two directly opposing principles: absolute denial of the self and absolute deification of the self.
In contrast to what was said earlier in the thread, I think both systems lead to absolute anarchy (another term that has gotten a bad wrap over the past few decades).
In true Communism, contrasting with the pseudo-Communist oligarchies of Marxism, Leninism, Trotskyism, etc., all individuals must be entirely equal. There can be no administration or 'higher power', because undoubtedly, when one man is placed above another, he will regard himself as superior. All individuals work toward the maintainment of everyone but their own personal self, and by the collective effort of those around that individual, he too is in turn cared for.
In Capitalism, there can be no government either. Governments levy taxes to maintain themselves, and the collection of taxes is a violation of the tenets of true Capitalism: the idea that a man deserves every bit that he earns. One might argue that a Capitalist government could work if administrators worked on a volunteer basis, but that would serve others' needs and would therefor compromise yet another tenet of Capitalism: one must work for his own gain and for that alone. Where Communist worry themselves with the welfare of others, Capitalists deny the need to care for others, focusing their attention on personal gain.
In either case, societal progression takes place based solely on the primary tenets of either self annihilation or self interest. Unfortunately though, neither system can be implemented on Earth. Capitalism works a little bit better because greed, the primary motivator, is innate and incorruptible (after all, it's already corrupt by modern standards), but underlying human goodness gets in the way in most cases. Communism is destroyed by greed and by egotism, the unwillingness to annihilate one's own perception of self.
In real-world situation though, there's no contest for me. Communism, while noble in cause, cannot be properly maintained. Socialism, which has become what I refer to as the ugly baby of Communism and Capitalism, tries to embrace two opposing principles and ultimately fails. Capitalism, in conjunction with minimal government involvement, takes the cake for me. Despite its apparently innumerable flaws, falls closest to its core values and provides the greatest happiness and opportunity for those under its influence.
And now for the disclaimer: Obviously, there is much more to be heard of both systems than what I have put forth, and some of the views that I have emphasized are neither widely recognized nor readily supported. In reference to my comments on Socialism, I mean no offense to my dear Canadian, British, etc. fellow members and have only my own myopic and ignorant views upon which to base my opinions. As far as I know, that should do it for now...