i.e do you prefer:
- technically grounded and plausible science elements (e.g The Martian)
or
- stuff so fantastical that it doesn’t even warrant trying to explain it (Dr Who, some Marvel/DC stuff, Star Wars)
Another way to look at this would be Sci-Fi versus Science Fantasy, perhaps.
- Old-School Sci-Fi like HG Wells centers around a core scientific idea and the consequences arising from that,
whereas
- Science Fantasy (more prevalent nowadays) only looks to science - or the impression of some science - to serve the fantasy devices it uses.
So which is better?


I hate zombies, but not all zombie stories are disqualified from the sci-fi mantle. If there’s a virus or nanites or something technological that triggers the zombification, it becomes arguable.
I won’t want to read it, but it might qualify as sci-fi.