You will pry CSVs form my cold, dead hands. When I have lots of data in multiple related tables where I would benefit from defined data types, I reach for HDF5

You will pry CSVs form my cold, dead hands. When I have lots of data in multiple related tables where I would benefit from defined data types, I reach for HDF5 or SQLite, but there are so many nice things to say about a simple CSV for lots of simply structured data. Super simple to stream compress/decompress, and the ability to use great CLI tools like xsv, and being able to peak at the data by simply calling less or head... it's just hard to beat.