I wasn't really even aware of the gauge issue with HDMI cables until today. While I knew there were different gauges for speaker wires, considering most HDMI cables were ALSO specced out using many other factors, I simply didn't even THINK about gauge as a factor. Then I received an HDMI splitter I ordered through Amazon's storefront so I can split the HDMI output from my PC to my monitor and my HDTV. It's a powered splitter and the very sparse manual that came with it specified 26 gauge cables, but I don't know if that was a maximum, a minimum, or a guideline.
At any rate, at that point I looked at the two cables I ordered with it -- a 1.5 foot cable just to hook it up, and another 6-foot cable that was pretty inexpensive... Both were 28-gauge. I just checked all my other HDMI cables I'm using with my TV and so forth, and they either don't have any specs on them, or they all say 28 gauge, EXCEPT the cord I'm using for my computer monitor -- and I don't remember where I got this one, but it's about twice as thick and has a sort of "fabric" exterior... I think it MUST be a lower gauge than 28, although that's a short connection, so if that cable's long enough I may re-purpose it for the TV from my splitter box, once I hook it up... It's a pretty stiff cable, anyway, which makes rotating this pivotable monitor a bit tough, which I sometimes need to do for editing documents and photos.
The longest cable I currently have is 12 feet (I got 2 12-foot cables, plus two bottles of screen cleaner and 2 screen cleaning cloths for $30 at Costco -- those two are both 28 AWG, but the cables look pretty good -- the little black one that came with my Blu-Ray player, by contrast, doesn't even have an AWG rating printed on it and looks pretty flimsy, but the picture on the TV looks fine, so I'm not complaining.