I thought the same thing about David Harbour. I have seen him as a bit character actor so I was stunned by how good he was as a lead. Really carried the role well. The little boys are also perfectly cast and given a great script that clearly understands the dynamic of "young guy friends from the hood". And at first I thought Winona Rider was a bad idea, but she managed the perfect blending of manic insanity with grounded realism. Finally, if there can be such a thing as perfect casting, the young actress who plays the girl with paranormal powers (Millie Bobby Brown) is simply stellar.It's brilliant. The acting, writing, production value, set and clothing design was just perfectly executed. Even the music is exceptional. The 80s music mixed with a constant homage to "John Carpenter esque" haunting synthesizer style sounds was flawless.
I'm not sure any debut season of a show since True Detective has been even close to Stranger Things in 2016.
David Harbour, the dude who played the Sheriff has been a bit actor in movies for years. He was excellent as the lead. This will clearly launch him into another tax bracket.