There is no good answer to this frequently asked question. It depends on a few factors around your intent, budget, etc…
The rules are as follows:
>For OS, because of booting and operation speed (Windows, MacOS, Linux etc), use SSDs. Which interface? The fastest available in your machine, which would be NVMe nowadays (est. 2024). For older machines, it would be SATA, which is also easier to configure in RAID arrays for more data redundancy.
>For storage, due to high capacity and lower cost per GB, use HDDs. Helium based drives have the highest capacities, but also the lowest rate of recoverability due to the Helium element, but, more importantly, the extreme complexity of the firmware and mechanical compatibility components, which are virtually impossible to deal with at this time. Why? Because the manufacturers are keeping the technologies secret, without making it available to the public. Reading patents is not good enough and R&D is very costly and time-consuming. Best interface would be SATA, and ultimately, SAS for high capacity and most speed at the expense of high cost, of course.
What brands are better?
In the data recovery field, it takes on average about 2 years for devices to start failing and come in for data recovery and a 3rd year worth of data collection to process trends regarding "what drive models suck during that 2 year span". So, it is difficult to make recommendations based on 2-year old products, as likely they are no longer on the market anyway.
Generally speaking, it is important to understand that HDDs and SSDs are increasingly manufactured with application specificity (basic home user storage/backup, gaming, NAS, enterprise/cloud storage, etc). People are stuck in the mindset of 10+ years ago, or lack the knowledge, or shop by "lower price", assuming all drives are basically equal to another. Due to the ever higher storage and speed consumer demands, things have been evolving fast, especially flash, which is what is used in SSDs.
>For HDDs, they all fail. We would be a smidge biased toward Toshiba, solely because they are slightly easier to recover most of their models compared to their counterparts. But, since they have been acquired by WD, along with the Hitachi/HGST HDD division, they are all kind of merging together in one or two model drives, just branded with different names.
>For SSDs, they are all guaranteed to fail due to their technological finite amount of write cycles. They are increasingly difficult to recover due to signed/locked firmware design, as well as hardware encryption. Samsung SSDs are somewhat better regarded, as they manufacture just about all important components. But, they have recently had a few models affected by firmware issues. Same with SanDisk, again a WD company. Overall, the more cheaper the SSD is, the worse quality. This article may provide a bit more insight: https://www.datarecoveryguru.com/edu/2020/8/9/usb-flash-drive-data-recovery-amp-chips-quality
Numbers on HDDs and SSDs Failures
A good reference, for larger data analysis of HDD and SSD failures, is provided by BackBlaze, a cloud storage provider, though most of their drives are enterprise models, which most small business and home consumers would not normally use. Here is a link as of 2023 for example: https://www.backblaze.com/blog/ssd-edition-2023-mid-year-drive-stats-review/
In conclusion, both Hard Disk Drives (HDD) and Solid State Drives (SSD) fail, often unexpectedly, especially SSDs. So, having a solid & verified data backup strategy is the best course of action. Don’t forget: could storage is “just another company’s computer storing your files”, so, though overall better, data loss and disasters happen there, too.