Nexus 6p. Mine self destructed due to a damned chip flaw, but was the first phone to have a camera that literally floored me. Every thing about the phone was the epitome of "more than the sum of it's parts". Bought a refurb cheap just to get another 2 years despite the known flaw.
I'd say that if most of the Nexus line, but 6p was the best. Absolutely treasure my now-useless but mint Nexus One.
Pixel just haven't quite done it for me, and that saddens me so much.
OnePlus had some great hits. I'm very fond of my Bacon, and and 7 pro. The 8pro was great too, but some of the special was.... less.
Looking closed at the moment to me...