Reliable External Storage
Backblaze has issued their yearly hard drive failure report. They use thousands of consumer grade hard drives for their cloud storage requirements, and keep statistics on which drives are failing and when.
Western Digital (WD) and Seagate are generally the biggest contenders in the consumer market, and most manufacturers use their drives. LaCie, for example, is owned by Seagate and LaCie branded storage contains Seagate hard drives.
It can be a little hard to parse, as different drive capacities have very different failure rates, but here's the PEBMAC quick-take:
Seagate drives fail more often than Western Digital, in some cases by a huge margin.
The higher drive capacities (12 TB vs 4 TB) tend to have lower failure rates.
HGST/Hitachi had the lowest failure rates, but these drives are generally only sold "bare" without an enclosure needed to connect it to your computer.
If performance is more important to you than looks, here's what I'd do:
Order one of these drives from Amazon
Order one of these drive docks
If you go this route, be sure to format the drive for use on the Mac before you start using it (many drives come preform mated for the PC, and while the Mac may be able to use it, it will be much slower than the Mac format and could be unreliable for things like system backups).
If you want reliability, performance, and looks, but money is no object, these are the bees knees.