I've been randomly messing around with Topaz Video AI for a couple years now. It's a neat tool but I have trouble ignoring the typical "tells" of AI upscaled footage (thinking primarily of a waxy look). That's probably on me for not tweaking the settings enough, although I've noticed the same...
This is my personal preference in order of what I think is the highest quality:
Blu-ray (Abandoned now but several studios released extremely high quality discs back around 2009-2012-ish)
Digital for HD content (Since DVD is the only physical option these days)
DVD for SD content (Anything old...