I went from the regular Sports band that came with my S0, to the Nike Sports band that I got with my Nike S2 watch, then to the solo loop I got with my S6. In terms of the length I've worn it, the Nike Sports band is the longest, but I now prefer the solo loop. Unfortunately, my solo loop broke in less than a year of use, so I went back to the Nike Sports band. I just bought a knock-off solo loop from Amazon, which is a bit more flimsy than the genuine Apple version. The texture of the genuine solo loop is slightly nicer, too. Still, I find the knock-off solo loop more comfortable than the Sports band, so I expect to wear it going forward, until it breaks, or when I upgrade to a new watch, whichever happens first. When I upgrade my watch, I'll see what bands / colors Apple offers then, and decide on what to get based on what's available.
so in sum,
1. Longest worn - Nike Sport
2. Most favorite - solo loop
3. Next purchase - undecided