Although expensive and difficult to use for networking novices, the Synology DS209+ offers awesome throughput speed and nearly all the features you could ever need in a NAS server.
The Synology DiskStation DS1513+ is easily one of the best multiple-bay NAS servers to date, performing superbly both as an advanced storage server and as the central host for a long list of home entertainment and business uses.
Synology DiskStation DS412+ makes an excellent NAS server for advanced home and small-office networks.
The DiskStation DS712+ is one of the best dual-bay NAS servers on the market, for both home and office environments. It's also one of the few that offer storage scalability for those who want to start small and add more capacity later.
The Disk Station DS410 is one of the most affordable four-bay full-feature NAS servers on the market. While it's overwhelming for novice home users, advanced users will also find it to be one of the best RAID 5-capable NAS servers for their home or small business environments.
For those who possess decent networking know-how, the Synology Disk Station DS710+ makes an excellent NAS server for any environment. It's best suited for home office and small-business applications.
The DiskStation DS1511+ is arguably the best five-bay NAS server on the market for both home and office environments. Novice and home users, however, might be intimidated by its setup software and the number of features it has to offer.
The Synology DiskStation DS213Air is a great network storage device for home users, especially those who also want to extend their Wi-Fi network.
Despite a few shortcomings, the Synology DiskStation DS411slim makes a worthy upgrade from its processor, the best-of-its-time DS409slim.