Depends on the anime/movie. Shows like naruto and full metal alchemist I go dubbed same with pokemon and yu gi oh but shows like Dr stone, that slime one, deserve sub. This is my personal opinion but there are just some shows that need it and some don't. Fun fact there is a debate on whether King of the Hill is better dubbed or subbed in Japan and it was rated one of the best anime's in japan.
I'm normally Dub if its available cuz I find that nowadays dubs get the love they deserve. I do sub from time to time as well when the simuldub isn't available to me.
I watch both these days dubs have little to no change in translation. I watch subs first as dubs come out little later and after some time i watch in dub if it was good. Older anime i watch dubs
Sub, even for something like the castlevania animation. Some people might say "but the original is english!!!". I just find that english dub sounds flat and emotionless most out the time, even if its the original language.
id say it depends on what im watching. if its in the background that i look at from time to time ill go dubs, but if its something im really watching the original voice acting flows better, so ill do subs then