There are primarily two form factors to consider ...
The 2.5" sata ssds offer nice price per GB. SanDisk and Crucial are two brands I've used that weren't as expensive as their Samsung counterpart, but still provided reliable value and performance. They have 500 GB - 1 TB drives on Amazon right now in the $70-$140 range, new. There's also the Samsung Evo in this form factor, but a little more.
NVME drives (M.2) offer better performance, but for bulk storage, that may not be so relevant. There are lower cost nvme drives in the $70-$80 range for 500 GB. I've only used Samsung NVME drives though, which tend to cost more, but they've never caused issues in my systems.