This may go without saying, but I think weather is incredibly important to stall in this meta and indeed this whole Gen, probably more so than for any other playstyle. The simple reason for this is that without a weather of your own you allow your opponent to, unhindered, let loose powerful weather-boosted attacks (specifically in Rain and Sun) that will eventually break down your few walls aimed at countering that weather unless you devote an unreasonable number of pokemon towards countering the particular weather your opponent carries, opening yourself up to the other weathers. When you want to run a weatherless stall team, said team can almost always be made better by tacking on Sand, the "neutral weather", and in doing so greatly easing the pressure of the two high-powered weathers. Having Rain on a stall team requires more care with pokemon choice (you can't run Heatran), but has the same benefit of easing the pressure from Sun and (to a much lesser degree) Sand, while being able to deal effectively with opposing Rain by more viably carrying multiple Grass and Water pokemon such as Ferrothorn and Tentacruel.
All that being said, since Sunstall is plagued by a SR weak Ninetales and an amplification of Steel-types' Fire weakness, and Hailstall is plagued by the Ice-type sucking, by far the most common stall types encountered on the ladder, for good reason in my opinion are Rainstall and Sandstall. Rainstall teams in particular lack diversity of pokemon, with almost all the best ones running Toed, Ferrothorn, Tentacruel, Celebi, a dedicated special wall, and a Ground immunity. While diversity of pokemon is lacking in such teams, as in all stall teams I find that the diversity of the matches one plays with them abounds, with each match a new experience. I have also enjoyed some degree of success with such a team, taking a Toed-Ferro-Cruel-Onion-Rachi-Gyara past 1900 with like a 90-30 record (good by my standards). Sandstall is slightly more varied in terms of pokemon, but full Sandstall usually carries: a sandsetter, a physically-defensive steel, a specially defensive steel (usually Heatran), a Ground/Flying, and two water-resists. I have found similar success with one of these teams in the new meta. Anything with Stoutland or without Rapid Spin (think Aromaticity) is, in my opinion, not stall; it is semistall.
The reason, I would submit, for the lack of diversity in stall in today's metagame is that with such a broad range of threats to account for, only very specific stall builds are able to cover every threat while providing the necessary tools of stall (SR, Spikes, Rapid Spin).