Best for quick setup
WD My Passport Ultra, from £67
It’s simple to add between 1TB and 4TB of external storage to a Windows PC: just attach this palm-sized drive over USB and you can write to it immediately (Mac users need to reformat first).
Best for security
iStorage diskAshur2, from £139
There’s an option to password-protect the WD drive, but a Pin of 7-15 digits is mandatory on the iStorage. In 128GB to 5TB versions, as a flash drive or disk, it encrypts all contents and will erase after 15 access attempts.