Depends on personal preference and what features each individual prioritize...there is no best smart watch.
Sure, the Smartwatch 3 does not have the best display when put up against competitor, but I still chose it because it has an always-on display yet still last 2 days of battery life, transflective LCD that is extremely visible even in bright and direct sunlight, highest waterproof certification for an android wear watch, uses microusb charging cable so you do not have to bring different charger/cable, has standalone GPS, the ability to change the band including the frame of the watch, all these combination makes the watch very practical to use and it cost lest than $300.