Originally posted by stevebrot ...or not. Vivitar are consistently good for most of the brand's history with some (Series 1) being excellent. Most Sears lenses are re-labled Rikenon (Ricoh) and are usually good. Samyang, except for current models, I would avoid.
To the OP...Due to the literally hundreds of brands and thousands of lens models involved, it is usually easier to ask about lens suggestions rather than lenses to avoid.
Steve
You have a point. However, it seemed a good place to start. Your comment about Samyang, for example, is exactly the sort of thing I was looking for. Ditto Sagitta's comments on the Sears 28-70 Macro, and much of RKKS08's post about "Lenses to investigate before buying". At the end of the day, though, it's engendered a useful, educational and enlightening discussion, the results of which I can put together in the context of everyone's input. (Thank you all.)