I currently have a Samsung Galaxy Watch 4 to replace my Garmin Vivoactive 3, but I prefer the Garmin. It’s got a bit less by way of bells and whistles, but I also think that the watch might have been overkill for the most part. I don’t end up using the onboard replies as much as I thought I would, and things like ECG and Blood Pressure monitoring are just troublesome enough that it’s not worthwhile (Blood Pressure requires recalibration with a proper machine every once in a while).
The only issue that I had with the Garmin was mostly that the body is a bit too fragile. It’s just plastic, so the corner will break off due to age, which is what happened with mine. If it wasn’t made of plastic, but more durable metal, like the Samsung, I’d still happily wear it. The battery life tended to be better too.
If it was still around, and not incredibly uncomfortable, a Pebble might also not go amiss. I personally don’t need a lot of features in my smartwatch (just timers, alarms, activity/HR tracking, and notifications), so a cheaper, hardier one would serve just fine.