Polar V800
Does all the things I need it to and would expect from a vaguely smart watch. OK, not the prettiest, but not obscene.
Tracks my pool sessions accurately enough, daily activity, GPS for my meanderings (don't be silly I don't do running, more or an animated shambling), waterproof to deep enough for me to troll around under the pool surface and should I feel the need, I strap on the HRM to see how close I am to cardiac implosion.
Lasts 2 weeks if I don't bother with the HRM and GPS. 3-5 days if I use GPS etc.
Does smart notifications so I can see which app is bothering me and now it even can control a go pro 4 (if that floats your boat).
Mono screen black on white or the other way around.
Got it on offer a while ago, effectively half price, can't complain really.