Demo Videos

Not specifically PLEX related but... Can anyone point me to some demo videos (like nature-scapes or something other than Big Buck Bunny) where the same video is available in various resolutions, bit rates, HDR, etc. I've tried web searches but I'm not finding anything that fits what I'm looking for. No real reason, just something to do on a rainy Saturday afternoon and maybe "stress test" things to see if I can adjust any of my configurations or TV settings to improve quality/performance.