Dunlop Volleys for 35 years or more. Unfortunately overseas production affected the quality on these, as with many once very reliable Australian brands.
There have been some before and in between the ones shown below.

 

Nike & Apple

 

Montblanc pens(love my 149)
Persol and vintage B&L Rayban sunglasses
Apple(for mobile phones)

 

I like my Carerra sunglasses!!

 

Collings Guitars

 

Holtkoetter

 

Yaesu (radios), Laphroaig, and Indian Motorcycle.

 

Loake, John Smedley, Barbour, Boss, Belstaff, Ralph Lauren, Hopetech, Laurent Perrier,Rayban, Oakley, Haglofs and Ron Hill.

Out of that lot the only let down have been a pair of Barbour boots that fell apart and a Boss jumper that did the same.
A zip broke on a Belsaff jacket that was 6 years old and the firm fixed it gratis which i was impressed with.

 

Hoka One One

I have an LV Wallet I bought 15 years ago and it still looks brand new, mainly because I avoid opening it of course

It has been incredibly loyal to me and I will return the favour one day and buy another.

 

I have 14 of their jackets currently, 8 of them waxed.
I also have knitwear, boots, polos short and long sleeved, shirts even aftershave.
My missus has Barbour jackets and so does our dog.

 

So are you a roofer by any chance ..??
The only shoe anyone had when I worked as a roofing guard installer with a mate in between rugby seasons many years ago…

 

https://www.autofinesse.com/en if you like your vehicle to look its best with minimum effort

 

Apple
Lamy Safari pens
Patagonia

 

Linn products

 

Never though I had any intense loyalty to any brand but on reflection I guess I do, the below purely subjective of course.
Audi, bought my first one in 2005, cant see past them for design and quality.

Musto for sailing waterproofs, for decades now, do exactly as they say on the tin.

And of course Guinness Stout

 

Ethnic Spirit and Vivobarefoot shoes (vivo need to up their game substantially regards making resolving widely available)
Lone Palm Vineyards Barossa red wines
Bernard Remy Champagne
Apple - phones and IPad pros
Ex Officio - clothing for travel
Glenn Wilson acoustic guitars (now that De Gruchy is dead)

 

Volvo
Quicksilver
J. Lindeberg
Adidas Stan Smith
Titleist

 

BEER!

oh... I guess thats not a brand...

Cold beer!

 

Ahh yes, Duff!

 

I award no exclusivity in any field, but the following brands usually have my preference in their respective area of expertise:

Apple
Armor Lux
Canon
Clarks
Di-Modell
Jabra
Land's End
L.L.Bean
Manurhin
Opinel
Sebago
Sony
Timberland
Victorinox