There is no right answer to this question. It all depends on who you ask. In terms of general American values, yes, it is important to be an individual. The first ten amendments to the constitution all guarantee and safeguard the individual . . . not the group.
Advertising is rich with the theme of individualism. Ads claim all the time how you should choose to be an individual and how their product will make you an individual. Which is super ironic, because if millions of people are using that product, it's not exactly individualistic. Let's look at some advertising slogans to help illustrate how prevalent individualism is.
- Spite tells you to "Obey your thirst."
- Corona tells you to "Find your beach."
- Scion's slogan is "What moves you?"
- Scion's other slogan is "United by individuality."
- Burger King at one point told you to "Have it your way."
I'm sure you've heard somebody at one point say "well that's fine for them, but not for me." There is a huge emphasis on being an individual. On one hand, I get it, and I think "being yourself" is important.
On the other hand though, I don't see a problem with people wanting to fit in either. The concept of a team is completely the opposite of emphasizing the individual, because the attitude is no longer "what's best for me?" A member of a team puts the group before his/her individual needs and wants. The question becomes "what's good for the group?"
To answer your question, no I don't think it is the most important pursuit in life for people to strive to be an individual. I think that because if everybody made that their number one goal, the world would be a very selfish and lonely place.