The election of 2008 was indeed a watershed event, but it also unleashed a great deal of ugly racial undertones in our politics (often accompanying very legitimate political positions.) I don't think anyone is saying that the problem of race is solved, but it seemed worthwhile to point that out. Aside from that, I'd agree that the Civil Rights Act of 1964 and Voting Rights Act of 1965 were major turning points. I'm not so sure about the Brown v. Board decision, which really reflected an ongoing process that still had decades left to reach fruition, and is being rolled back by de facto segregation in many major cities today. Along with the events mentioned above, I'd add World War II, which really gave life and impetus to the Civil Rights movement.
I would also agree with the election of 2008, as it demonstrated social progress whereas many of the achievements of the Civil Rights Movement were legal progress, and difficult to enforce as always. That is not to take away from other achievements, however. The Montgomery Bus Boycott was significant, as it was the successful use of black economic power to institute change. And I would agree with other posters that the Voting Rights Act was the crowning achievement of the movement.
There are also psychological boosts to consider, arising from all these improvements. It seems obvious and right to us now that a black president should have every right to be in the White House but as he said himself, we are not so very far away from those days when such a thing would have been unthinkable. Morale and peer example are hugely aspirationally valuable for young people - it gives them a 'can do' mentality.
The right to vote, which was guaranteed by the Voting Rights Act of 1965 is one. A second is the illegalization of racial discrimination. This came from things like Brown v. Board of Education and the 1964 Civil Rights Act. Finally, I would say that the decision in Loving v. Virginia, which made it illegal to ban interracial marriage was important as well.
I agree with #5. Just as important to this question is not only particular laws that have been passed but also the visible success of African-American figures in society. Seeing Barak Obama occupying the White House is more of a blow for equality than any law could ever be, as it shows that whatever is said as part of political rhetoric is actually now based on reality.
Another notable achievement was having Collin Powell as a United States four star general. He was also the first African American Secretary of State. This was a huge achievement, which should not be forgotten. He was also the National Security Adviser and part of the Joint Chiefs of Staff. In light of these points, he was the first in many ways.
I, also, agree with post #5. For Barak Obama to be elected President, the lines of oppression and repression have certainly been weakened (for lack of a better word). Outside of that, I agree that the equality laws have been of the utmost importance. While they, still today, have people who question them, the lines are becoming less and less rigid.
Aside from the achievements already mentioned, I would stress any and all changes that have helped African Americans benefit economically, especially by owning property and building businesses. Economic power and liberty are often crucial to the growth and maintenance of social and political power and liberty.
Aside from those in the previous post, I would consider Jackie Robinson's breaking of the color barrier (1947); the defense of the Scottsboro Boys (1931); and the founding of the NAACP (1909).