Hellraiser Bloodlines is both a prequel and sequel to the first three films. It’s a great movie but does not fit the OP’s criteria.
Her World of the Five Gods tales have a number of standalone stories that could be read independently of each other.
The Hallowed Hunt came after Curse of Chalion and Paladin of Souls. Same deities etc., but with shamans thrown in, and otherwise quite independent (set several hundred years before, in fact).
And the Penric novellas in the same world are completely independent of the others - again, aside from the deities / shamans. I don’t know that any of these would qualify as “prequels” though.
On that note, does Wonder Woman count?
How about the TV show Gotham? I think my wife had a much easier time following and enjoying the show without all the baggage a nerd like me carried into it.
I’ll second this. I found Morse unwatchable, but I liked Inspector Lewis ( a sequel that I watched before I found out that Laurence Fox was a nazi ) and love Endeavor. Lots of great stories and a perfect job by Shaun Evans. You can see him turning into annoying adult Morse, thankfully he doesn’t get there.
Yeah, Endeavour can only go for one more season, because it has caught up chronologically with the beginning of the Morse series. Besides seeing Endeavour turning into a PITA, we’re seeing him turn into an alcoholic. I’ve watched the earlier seasons over and over a million times. (Trove is utter perfection with a punch line that gives new meaning to the statement, “you never saw that coming.”) Seasons 7 & 8 were abominations. Another problem with the fadeout/transition is explaining why Fred and Joan Thursday never get a mention in the Morse series (or books, for that matter-- not that I’ve read the latter).
I also love Lewis, especially the earlier seasons. I adore Hathaway the character. If there’s a type that I’m a sucker for, it’s a troubled, intellectual ex-priest or seminarian. (Scars of a Catholic girlhood.)
Laurence Fox is a NAZI??? 
(Oh God… I just looked that up…)
But I’m not sure that one makes much sense without the other books. “The Man Who Sold the Moon” is a perfectly satisfactory standalone.
[quote=“mbh, post:54, topic:972657, full:true”]
We all saw what you did there.
You’re killing me.
my response is below since the quote function didn’t go all the way down … :
yall need to go stand in the corner and think about your life choices 
All of these Oedipus Rex jokes are entirely predictable.
Oedipus wrecked it for you?
And no matter how often you try to avoid them you seem fated to meet them.
Casino Royale (the Daniel Craig version) was more of a reboot than a prequel, bu it was technically both and one of the best films in the series.
Wish You Were Here was a prequel to Personal Services, but not exactly promoted as such. I found it a much better film.