In my limited experience with this kind of stuff, here's what I found, with the same amp (McIntosh MA5200), same speakers (Revel Performa 3 F206 - 8 Ohm nominal load) and same lengths of (copper) cable (6 feet).
Going from 16-gauge Monster Cable to general all-purpose multiply shielded 16-gauge AudioQuest cable (cut from a large spool at the stereo shop) yielded a slightly improved sound quality ... I think. However, that could have been me just trying to convince myself that I could hear an improvement. That's how slight the improvement was ... if there was one.
Going from the same multiply shielded general all-purpose 16-gauge AudioQuest cable to 12-gauge AudioQuest Type 8 definitely yielded better sound quality. The improvement was, admittedly, relatively slight but immediately palpable or "hearable", if you will. I didn't have to strain or listen hard or for very long to notice the difference and I seriously don't think it was me trying to justify the expenditure. She Who Must Be Obeyed, never one to hesitate to give me a brutally honest opinion, when asked or not, said she could hear a significant improvement, as well.
Now, would going to good quality 10-gauge speaker cables and/or super expensive exotica cables with these same components yield even better sound quality? I seriously don't think so. I've done serious seat-time with the same components in stereo shops using super expensive exotica cables (e.g. AQ Robin Hood - apt name, don't you think ... rob from the poor; give to the rich - sorry; couldn't resist; Nordost; Kimber; Transparent). Granted, the acoustic characteristics of these disparate sound rooms varied, the wiring in the different buildings was likely different and all that jazz, and they were all using banana plugs (I'm a firm believer in high-quality spades at both ends, if possible). However, I still didn't hear any significant differences or improvements in sound quality from my home set-up. There are some who firmly believe they can, indeed, hear infinitesimally small improvements or, rather, differences in performance of various reasonably good and/or high-end quality speaker cables and connectors. If you are convinced that you can hear a difference in performance and/or sound quality that appeals to you versus one cable, connector or whatever over another and think it's worth it, then go for it!
Now, I don't have a Mikey Fremer system that would justify super expensive speaker cables, connectors, etc. I'd have to build a dedicated sound room to justify anything like that. Maybe someday ... if I win the lottery or some long lost relative leaves me a million-dollar inheritance.