The NY Times publishes a guide to the "Essential Stephen King" and...it's not the greatest. They include THE STAND, 'SALEM'S LOT, FROM A BUICK 8, THE GUNSLINGER...I mean, I'm a pro at reading King and that's not where I'd start.
https://buff.ly/2L0zKmY 
1/1

Start with the novellas!
SUPERNATURAL HORROR - "The Mist" from Skeleton Crew
MORE OF A THRILLER - "A Good Marriage" from Full Dark, No Stars
NO HORROR THNX - "The Body" from Different Seasons

Ready for a novel? Try something relatively compact about people self-isolating like:
MISERY
THE SHINING

Want a novel about kids?
FIRESTARTER
THE GIRL WHO LOVED TOM GORDON
CARRIE

Want something really out there and messy and horrific?
'SALEM'S LOT
PET SEMATARY
DESPERATION

Want a big fat monster of a book?
11/22/63
DUMA KEY
THE STAND

Want King working in his more literary mode?
CUJO
REVIVAL

Want something goofy and off-the-wall but relentlessly entertaining?
CELL
THE TOMMYKNOCKERS
UNDER THE DOME

I spent 5 years reading everything King published (up through 2017 and that's how I'd roll. You can get the full write-ups over at my re-read on Tor: https://www.tor.com/series/the-great-stephen-king-reread/