#1, One = Objectivist
The individual. his/her happiness, his/her wants and needs to achieve happiness, is paramount in Objectivism. All things done by an Objectivist should be entirely self-oriented with the sole purpose of achieving his/her own happiness (marriage, job, . Therefore, the number 1, individualism, is the Objectivist. No?
"Objectivism holds that there is no greater moral goal than achieving happiness. But one cannot achieve happiness by wish or whim. Fundamentally, it requires rational respect for the facts of reality, including the facts about our human nature and needs. Happiness requires that one live by objective principles, including moral integrity and respect for the rights of others. Politically, Objectivists advocate laissez-faire capitalism. Under capitalism, a strictly limited government protects each person's rights to life, liberty, and property and forbids that anyone initiate force against anyone else. The heroes of Objectivism are achievers who build businesses, invent technologies, and create art and ideas, depending on their own talents and on trade with other independent people to reach their goals."
- Atlas Society Website.
But as described in your response, the achievement of happiness necessarily requires fundamentals and principles of Objectivism that includes "respect for the rights of others", so for me "the number 1, individualism, is the Objectivist" doesn't quite capture the entirety or essence of Objectivism. Rational self interest derives from the practice of living by objective principles, rather than leading to Objectivist principles and action.
Maybe I'm over complicating the issue, but the historical attacks and arguments opposing Objectivism have most often concentrated on the concepts of being the #1 and selfish individual. Being a rational self interested individual is the result of living as an Objectivist, not being #1.
The individual exercise of reason — not the individual pursuit of happiness — is paramount in Objectivism. Happiness is an appropriate goal for the individual to pursue; not the only permissible goal, but an appropriate goal.