Best Alignment Protractor?

I've hated needle/cartridge mistracking since I was in my single digits. I've always hated spitty sibilants, buzzy vocals & scratchy violin sections.  And don't get me started on hashy-sounding pianos. It's a major reason why I lived with a Shure V15 cartridge for many years. It's one of the reasons I was an early convert to Compact Disc. I got to say, though, that meticulous cartridge alignment and ongoing improvements in cartridge technology have largely made mistracking and end-of-side distortions a thing of the past.

I have Mints, Accutraks, Uni-tractor, original dedicated Wallys, and an older multi-arm Wally. The dedicated Wally’s are my favorite by far. I just wish I had one for each of my tonearms. Fortunately, the multi Wally fills in most gaps. Mints are good, too, but a bit more difficult to read; the printed, rather than inscribed, lines are slightly less precise, although this is truly splitting hairs.

I have a bunch of gauges, including the Denneson and CartAlign but my favorite is the original arm-specific Wallytractor, just like @wrm57. I do not think they are currently available.

I currently own a Feickert and a Mint.  

The Feickert gets me quickly to where I can tweak by ear (and o-scope in my case) which is the final step in any alignment no matter how accurate.    

Mint's protractor based on perfect theoretical alignment is admirable but not as quick, as easy or better.

Sorry, but there is no single "perfect theoretical alignment." There are several well known alignment schemes. They even have names, and some are promoted by tone arm manufacturers.

None of them is perfect, as the alignment of all of them is wrong almost all of the time.  The issue come down to where you want your mostly misalignments to be.