Any of the fluoroelastomer pin-and-tuck bands bands, by a long shot. Those are the most comfortable overall, and they do not care about sweat or chlorine. I like the Nike band the most. (The silicone clone bands are equally comfortable.)

Been a huge fan of my Nike band. As my wrist seems to swell, sweat, etc., I can just use the side rows of holes to make minor adjustments instead of making bigger size changes just down the middle.

I use a Sport Loop and it’s been great. It’s much nicer than the Sport Band - I found that they would collect sweat and water underneath until I took the watch off. It’s comfortable enough to wear all day.

The Nike pin tuck sport band.

Used the Nike sport band for the first 5 months of owning the watch, switched to the Nike sport loop about 5 months ago. Been training indoors and out, pool swimming 3-4x a week every week throughout, etc. etc. Neither has shown any signs of wear and in my opinion, I'm a fan of the loop.

Sport band for swimming. It's very secure and seems impervious to chlorine etc. Also easy to dry completely after the workout by wiping with a towel.

Sport loop for running. I prefer a tight fit and the loop's infinite adjustability does the trick. Don't care for the loop when swimming, though, as it retains water and I don't like a soggy band on my wrist afterwards.

This is similar to my experience. I’ve had a couple of different bands but I liked the Nike one best, due to the fit and the feel of the materials used.