I have a weird fascination with NoSQL Databases. I like to tell myself that the future is free of Relational DBs, even if I don't believe it. Of all the NoSQL Databases I have tried (Mongo, Couch, Cassandra, Neo4j, Redis), I consider MongoDB to be my second favorite. It is easy to get up and running, and I find the Mongoose ORM both intuitive and powerful. I have done all kinds of work with Mongo, from query optimization to sophisticated aggregation to powerful text search to GeoSpatial querying, and I have yet to find something that was truly difficult to do with the database!