Interconnects currently are mostly Pro-Co XLRs from Sweetwater Sound. I have also had a few other brands but didn't notice any sonic difference. RCA cables are a mix of no-name-came-in-the-box, Emotiva X-series (on sale, bought with an amp), some old Fulton, various other brands, and some homebrew cables chosen for excellent shielding and low capacitance. I have a variety of speaker cables around as well but currently using off-the-shelf powerline 10 AWG for my mains and some type of Monster cable ~11 AWG for surrounds and rears (dealer threw in a spool years ago; I used to have the sheet just for laughs but tossed it long ago).
By and large many years of DBTs and such (including secretly swapping cables to see if people noticed) have convinced me there is essentially no difference among cables that are adequate to do the job. Adequate means proper shielding for interconnects, low capacitance where required (phono, tube stages), and for XLRs the ability to lift ground at one end to break a ground loop. Speaker cables need to be large enough to do the job, which for me is a bit narrower than the typical loss charts. In addition to loss, many speaker designs assume a nearly-ideal voltage source driving them and so resistance (and to a lesser extent capacitance and inductance) can tweak the crossover slightly. Unless the wire is really undersized I have not measured significant changes, but switch from say 16 or 14 AWG to 12 or 10 AWG and you can measure the change in frequency response with speakers that have large impedance excursions (not uncommon). Usually a fraction of a dB, so not audible, but measurable.
I think day-to-day changes in my mood and physical state generally swamps such minor changes in the system. Time and again I have convinced myself I heard something different, only to discover that either I could tell no difference in subsequent trials or that the "new" sound I heard in the recording was there all along and I just happened to notice it since I was listening more closely.
There are cable designs, interconnect and speaker, that do filter or otherwise color the sound. I tend to avoid those.
FWIWFM - Don