I used to be a buyer for an artists supply concern, so I'm very familiar with tapes, in general. When you want a tape you can rely on, always go with the top of the line product from 3M. This is usually labelled "Scotch", but there can be several different quality levels in any particular product line. 3M also has a couple of cheaper brands, "Highland", and "Tartan".
The trouble with real gaffer's tape is that it uses a natural latex-based adhesive that doesn't last very long in storage or usage. The cool thing about real gaffer's tape is that it's very strong, but leaves no residue behind when you peel it up. Being trained in Theatrical Technical Production, I've used real gaffer's tape in it's intended purposes, and it performs like a champ. Beware of cheap imitations. If you want the real thing, you'll probably have to source it from a reputable theatrical supply house.
I'm quite fond of the 3M/Scotch Extreme Application Packaging Tape (#8959), which is a packaging tape with a woven fiberglass layer. This stuff is practically impossible to break, but breaks down fairly quickly in UV light (sunlight). Of course, this isn't really "duct tape", per se, but it's quite useful when you really need extreme strength in a tape. I've used it to attach 4 mil plastic to my car to cover a couple of broken windows, and a year later, I still have residue on my car. It's getting harder to find, and it's quite expensive, but I usually get mine at Staples in a 50mmx20m roll on a one-hand dispenser (with an incredibly sharp and dangerous cutter). #8959 has a tensile strength of "150 lb/inch longitudinal and 50 lb/inch width in cross direction" (translation not included). If your needs are more unidirectional, #898 Filament Tape has a 380 lb/in width strength.
If you can find it, try 3M's 130-series Professional HVAC Duct Tape (#131, 132, 133 in 10, 20, 50 yd rolls, resepctively), or #138 All-Weather Duct Tape.
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Gemma Seymour (she/her) @gcvrsa