Which smartwatches would be best to pair with a Pixel?

So I'm already considering if course to get a Pixel Watch, and it's right up there on my list, but I wanted to hear about other people's experiences with other smartwatches.

I saw that OnePlus' new watch is getting appraisals, and obviously there's Samsung's Gear, but I heard those have many features locked away when not paired with a Galaxy phone.

By the way, I'm not looking necessarily for the highest-end watch or the newest one.

Any thoughts?