It's amazing how cheap memory has gotten. They have excellent read/write speeds and as far as I can tell they are built to standard and have good durability. The price is cheap enough to consider them expendable or to lend them (even to less reliable friends). Color coded but you can attach a small sticky label for identification if you wish.
Titan Gray Samsung BAR Plus 256GB USB 3.1 Flash Drive (MUF-256BE4/AM) with Up to 400MB/s Transfer Speed
69 Review
Kingston DataTraveler SE9 32GB USB 2.0 Flash Drive for Reliable Data Storage (DTSE9H/32GBZ)
69 Review
Samsung BAR Plus 128GB USB 3.1 Flash Drive - 400MB/s - Champagne Silver (MUF-128BE3/AM)
65 Review
Kingston DataTraveler flash drive 100 G3 256 GB, 1 pc. black
74 Review
18 TB External HDD Western Digital WD Elements Desktop, USB 3.0, black
95 Review
2 TB External HDD Western Digital WD Elements Portable (WDBU), USB 3.0, black
84 Review
8TB Seagate Backup Plus Hub Desktop Hard Drive with Data Recovery Services
56 Review
2 TB External HDD ADATA DashDrive Durable HD650, USB 3.2 Gen 1, Blue
55 Review