I love Vertica

It has been my favorite database technology for the last several years. It has shaved off hundreds if not thousands of engineering hours for my team, had we had to implement the same sort of product features backed by traditional database technologies like MySQL. The performance of the system is impressive, and the customer support is responsive whenever the occasional technical issue pops up (which doesn't happen very often compared to other databases we use *cough* Mongo *cough*).