What external hard drive do you use to back up data?

Lots of WD Externals. These days I try to get the USB-C Ultra ones but that means upping the price. A few external SSDs also, most WD with some Samsung sprinkled in. While I have doubt about the SSDs long-term storage capability, the transfer speed cannot be denied. 2TBs HDDs and 1TB SSDs are of affordable value and price to size ratio. One WD had failed on me after all these years, an old 1TB unit. Never tried Seagate, and I can't seem to find any more Toshiba. I have some Toshiba HDDs and they seems viable.

One SanDisk SSD was dead on arrival so I avoided it despite it being the cheaper option. I think it's something you gotta diversify and find your own opinion if you can, because everyone will give different answers, and what is available to your locale may be different. If you are truly scared about such thing then don't cheap out.

i dont lol, for 15 years i have been a pc user a hdd or ssd never died on me for a reason that wasn't explicitly my own, just treat your drives good, make sure they're ventilated not dusty etc, oh and don't buy toshiba

Can I count NAS as external storage? Synology DS218J with 10TB + 8TB WD Red Pro.