Any name-brand drive. These $15 drives are commodity items, and one is about as good as another. We use whatever make happens to be most readily available or cheapest, including (alphabetically) Mitsumi, NEC, Sony, Teac, Toshiba, and probably several others we've forgotten. We use Teac 235HF units by choice, but that's probably just from habit. If you have a choice, pick an FDD that uses a shrouded connector for the data cable.
Floppy Disk Drive (5.25")
None. Although we keep one or two around on general principles, the 5.25" FDD is obsolete except to read old 5.25" diskettes, most of which were written so long ago that they are now probably unreadable. As of June 2002, new 5.25" FDDs are still manufactured and sold, but few vendors stock them and they are now very hard to find. If you need to read an old 5.25" diskette, contact your local computer store, which probably has a stack of 5.25" HD (1.2 MB) FDDs in the back room and will likely give you one for the asking.