If you had to pick, what are some of the brands you think are most overrated or underrated based on what you’ve heard? 
Can be any type of cable
Drat I thought this read 'bands' not 'brands.' Was about to add red hot chili peps as most overrated. Maybe I'll start that thread separately ;)

Typical responses by a guy that promotes his cheap stuff and puts down quality equipment. Plus he gets paid for every time he mentions his speaker brand that he gushes over the top everywhere he can. Plus he needs to respond twice so he gets his digs in on quality equipment. Too bad he can’t read what the OP wanted.
Underrated:  The tremendous value available from the Wireworld line.  Check the quality of cable constructs considering their price versus other brands. 

Overrated:  Kimber.  Even their Select line of cables don't have the continuity of sound they should have for the asking price.

Overrated big guns, underrated small companies and snobbed ones.
Some of my list, ML, Wilson, B&W, Focal, Clearaudio....overrated
PMC, Bryston, Lavardin, Leben....underrated.
Please... Cables! Cables!!! 

Virtually all cables have been becoming overrated/obsolete since the appearance of Bluetooth and similar technologies.