I know this has been asked before, but it's been many years since I checked in, so looking for recent recs on this:

Have a family member with many (at least thousands, although we don’t have to do them all at once) negatives that they want to get scanned.

Any companies you can *personally* recommend?

@Drwave Strong recommendation for DigMyPics in Arizona. I’ve used them for scanning negatives (and prints) multiple times over the last 10+ years and have been very satisfied every time: https://www.digmypics.com/negative-scanning
Photo Negative Scanning Services | Convert Negatives to Digital - DigMyPics

Bring your old film negatives back to life with DigMyPics' professional negative scanning services. Our state-of-the-art technology ensures high-quality digital conversions, preserving your moments in stunning clarity. Ideal for archiving, sharing, and reliving your precious memories. Experience hassle-free service with our expert handling and fast turnaround. Start your digital transformation today!

@Drwave I punted on this kind of question by buying an Epson scanner and fooling myself in thinking I'll get to it.
Someday...
https://www.filmscanner.info/en/EpsonPerfectionV850Pro.html
Test report film-flatbed-scanner Epson Perfection V850 Pro transparency unit: experiences report; image quality, scanning slides, medium formats

@Drwave we used ScanCafe and the results were excellent.
@jsnell Thanks! I seem to remember that being one of the best ones last time I checked - good to know it's still well regarded.
@Drwave I used https://www.memoriesrenewed.com/ to scan and correct 8000+ slides and negatives of my late father and brother. The team was incredibly helpful.
I was able to get the corrected and uncorrected images in TIFF and JPEG. They duplicated the naming and numbering used on the original slides, making it very simple to add metadata from the paper photo diaries I have.
Total time door-to-door was about 4 weeks.
Memories Renewed

Memories Renewed® specializes in preserving photo and video memories so they can be enjoyed in today's digital age. We convert a wide variety of formats including photos, slides, negatives, videotapes, audio cassettes, and 8mm/16mm film.  Flexible output and viewing options are available to fit the needs of our clients.  Our studio is located in Minnesota, but we have touched the hearts of people around the world.

Memories Renewed