The only time I’ve heard a near "transformational" experience with a cable was (strangely) the old Zu Mobius headphone cable on Sennheiser HD650. I’ve tried a number of cables on those headpones, and many more cables on different headphone models. The Mobius/ / 650 was the largest change in sound, by far - and all of it "in the right direction" (that’s rare). It essentially notched the humble-classic HD650 up to a next level headphone. I’ve even had 4 different examples of the Mobius over years, and its impact was consistent (not a fluke). It's probably relevant that the Mobius was designed for that *specific* headphone, and the headpone needed some "help" out of the box (too dark).
Beyond that I’ve certainly had a few cables I think make a "nice" impact, but nothing I can’t live without, honestly. And frankly, the "wow" impact you get from a new cable tends to diminish over time (except the Mobius, lol). The next biggest impact I’ve expreienced (down from Mobius) would be speaker cables, where I tend to like a good amount of solid silver - Audioquest Kilimanjaro and Wildwood being my favorites, so far.
I generally LIKE the effect of silver cabling in my systems, but often the results are not continually additive - you can add too much and start to regress your system’s musical balance. That goes doubly (or triply) for tweaks, in general. A lot of times I’ve caught myself trying to make excuses for why I need to buy that next new cable lol. At the end of the day, it’s not a very per-dollar effective vector to increased long-term satisfaction.
