NLS user since 1997
I've used the NLS data to learn about wage dynamics in a number of settings. First, I used the data to look at wage losses for workers displaced from their jobs for different reasons. Second, I used the data to consider whether or not certain worker characteristics (like marital status) have causal effects on wages. Third, I used the data to determine whether or not the size of the city in which a worker resides has a causal impact on his or her wages.
The NLS is ideal from a number of different standpoints. First, it contains siblings, which makes within-family comparisons possible. Second, it contains extremely detailed labor histories for each respondent, which is perfect for my field of study. Third, it contains standardized test scores such as the ASVAB, and that has assisted my current research on the way in which firms learn about workers. Lastly, since this is a longitudinal data source, it allows for inter-temporal analyses. This is, I think, one of the best data sources available for most practical research questions.