Hands down the best. I even have a full rack mounted server setup with Sonarr and Radarr that’s full of content, but Stremio is so friggin easy. Especially useful for the stuff you will only ever watch once.
Second stremio. I use the torrentio addon without rd but always with vpns. It’s a backup for me for when my main nas goes down so I don’t want to pay for rd.
I have streamio + Torrentio + real debrid and works great. I pay for Amazon prime but prefer to watch series in the streamio since it doesn’t drop the resolution ever.