Okay, i'll try to get into this! Seems like good fun :)
My nomination will be
Balance/Semi-Stall (dunno if this term still exists tho). For starters, please check out these two wonderful, albeit old teams from the DPP era:
Team Ikki Tousen - Earthworm
Rotom, CHARGE! - JabbaTheGriffin
Both of them use a strong defensive core of four Pokémon, one Set-up Sweeper that gives Stall a hard time (with the help of Entry Hazards and/or other passive damage provided by the aformentioned core) and a Scarfer that acts as the failsafe to the rest of the team.
The beauty of that particular playstyle comes with its flexibility: These teams have two win-conditions, a more defensive one via Hazards (Spikes, Toxic etc.) and a more offensive approach thru the use of a dangerous sweeper or even the Scarfer after the opponents team is sufficiently weakend.
One thing to note is that you obviously can't cover every single threat with a defensive core of just four pokémon. That means you still have to play smart and kinda active with your defence, e.g. clever (double) switching and so on. However, a well-build balanced team will have just the right tools to beat nearly every other playstyle because of its various options. It then certainly depends on the players ability to figure out their best win-condition every single match and act accordingly.
Its not an easy task to create such a squad by any means, but it will be an interesting one for sure, cuz there are many different pokémon suited for a job like this. With the help from a templet like the one displayed on Jabbas and EWs teams, i'm pretty sure we will be able to build a good one as well :)
If we choose Balance/Semi-Stall as our playstyle, i would generally recommend a weatherless team, because it simply generates much more freedom within the teambuilding process. However, i really like the idea of using
Hippowdon for a style like this: Its amazing on balanced teams, because it acts as an effective mixed wall (good overall bulk and a godly typing) with an instant healing move and the ability to provide crucial passive damage (Rocks and Sandstorm) plus a Phazer all in one. Just a really good pokémon itself (unlike Politoed, Ninetails and Abomasnow) that won't limit our future possibilities at all!
Kevin Garrett Stall - Kevin Garrett may fit as an example for a team that utilizes Hippowdons strengths to its fullest.
Have a nice day