RE: Under-rated Archery products...
Steelforce BH (they get some good publicity granted, but their CS is unreal!)
Nearly all of the "cheap" bows. Martin, Bear, Pearson (and a few more)...they all have a few models that are a ton of bow for the dollar.
And while its not a single product I think the benefit of having an better aftermarket string/cable is unknown or unbelieved by a lot. Best $40 bucks I've ever spent on archery.
Anchor Sight...Don't have this one yet, but on another forum everyone who tries it loves it...even if they go back to a peep for 3D or spots...they keep it for their dedicated hunting rigs. I've never seen an advertisement for it anywhere.