Absolutely terrifying and endearing. I love the Losers. Bill Skarsgaard is massively unsettling as Pennywise. Beautifully shot even when we're seeing nightmares come to life. The Practical and CG effects blend really well.
I don't care about Chapter 2 right now. Chapter 1 was great and I want to enjoy because it gets everything right about telling a complete story within a larger narrative with room to grow.
Andy Muschietti nailed it. Props to him.