I think discounting all of fanfic because of the objectively awful cursed child is a mistake, there’s a lot of good stuff from talented writers out there

There are loads of fanfics which are much better than The Play Which Must Not Be Named. If that was your first (or only) exposure to fanfic, I can see how you would be scarred.

My go-to recommendation is Grave Days (FFN and SIYE), by Northumbrian.

It picks up immediately after the battle (right down to Kreacher’s sandwiches) and consists of 15 chapters that are canon compliant to the books. Northumbrian (in my opinion) comes closest to nailing JKR’s writing style, while also incorporating some excellent worldbuilding.

If you want to give it a try, there is the very good Victoria Potter series: https://archiveofourown.org/works/13795605/chapters/31714617

Victoria Potter had always known she was different. No matter how hard her Uncle Vernon and Aunt Petunia tried to pretend otherwise, she could do things they couldn’t, and see things they wouldn’t.

It was only when Professor McGonagall of Hogwarts School came to visit that she realised just how different she was. Sorted into Slytherin, in her first year at Hogwarts school she would find true friends, learn magic, and discover the secrets of the Houses of Hogwarts.

Magically talented, Slytherin fem!Harry. AU world with a canonical tone. No rehash of the stations of canon. No bashing. No kid politicians. No 11-year-old romances.

Another great recommendation is The Changeling: https://archiveofourown.org/works/189189/chapters/278342

Ginny is sorted into Slytherin. It takes her seven years to figure out why.

The style is very good, and the story quite fascinating.

Finally, if you are into next generation stuff, Questions and Answers: https://www.fanfiction.net/s/3954448/1/Questions-and-Answers

When the past and present collide with the Potter/Weasley children… A bit AU with characters’ names and some pairings.

Some of it made it to my headcannon.

Let me know if some of them were interesting to you!