This will likely be downvoted to hell, but personally I'm a fan of the service 23andme provides. It has aggregated scientific knowledge across a large number of domains to provide an end-to-end pipeline for ancestry prediction, kinship analysis and phenotype prediction.

It's a service built on learning algorithms to correlate features (DNA SNPs) with diseases. As with any learning algorithm, results should be interpreted with care. That doesn't lessen the fact that predictions it provides can be helpful.

As an aside, 23andme has a solid API. It's opened up (with consent) a huge DNA dataset for developers to mine. I'm excited for the science that can be learned from this data.