Different cultures answer this question differently, and usually, groups who value the individual as more important are branded as more selfish than those who value the group and uniformity more than the individual.
But is that really true in practice?
Theories are nice, but how does this play out if a society lives the theory?
This is what I have observed in my various travels:
If you only look at what's good for the group, not the individual - well, we've tried that as a species several times. Did it really go so well? Communist countries, where the group is the ideal, were they all filled with selfless individuals, who self-sacrifice themselves for the group?
Now take a look at societies that value the individual. Are they all filled with selfish people who never help anybody else?
In my personal experience, societies that value the individual more highly than the group tend to be more pleasant to live in as an individual - which is hardly surprising, given that the individual is allowed more freedom. What IS surprising, though, is that they also tend to do much better as a group as well. For some reason people tend to work together better when they CHOOSE to do so, after they developed their individuality, than if they are forced to do do by the culture - look at how well the USA does as a whole - or take a look at the German football team. China has embraced self-interest, and all of a sudden they are becoming the next world power.
Individuals who think of others first do the most good in the world - no doubt - but in my experience they do so AFTER they developed as individuals and therefore as leaders and because they choose to do so freely.
If you try to force people to be selfless, you won't get selfless people - you'll get people who are very good at faking to be selfless while doing everything to distinguish themselves as special, profit over others, and to propel themselves upwards by dragging others down - quite possibly by calling them selfish - because there is something within all of us that needs to be special. If you suppress that by forcing the individual to conform with the group, it will come out in hidden ways. If you support it, it may well be the one thing that supports the group the most.
There is no healthy group without healthy individuals, just as there is no healthy body without healthy cells.