You know what I've not heard a lot of these days? One of the nastiest, most vicious Pokemon that ever graced NU has somehow stepped down from the spotlight, and people just don't seem to be using it anymore. I believe that people think that Zangoose is too slow for this meta because of all those new drops, and the rise of the standard speed tier to beat, which Zangoose just misses out on. My personal opinion is that this is what I like to call "paper waste" (something that may be true on paper but not in practise). People just need to adapt, and mabye try a slightly different Zangoose set to the one they used in past stages. Only like 6.5% of Zangoose are running an Adamant nature nowadays, and I don't understand why. Think about it. Zangoose is outsped by Jynx, Primeape, Scolipede, Charizard... Pokemon that it would definetly enjoy having a more powerful Quick Attack against.
Jynx is guaranteed to be OHKOd by Quick Attack after Stealth Rock with an Adamant nature, and it still has a very solid chance of KOing after just a layer of Spikes or Life Orb recoil. Primeape is a Pokemon that is constantly weaving in and out with U-Turn, and wearing itself down by Spikes (which imo should ALWAYS accompany Zangoose, and they're so easy to get up and keep up in this meta). An Adamant Quick Attack does between 82-97% to Scarfape after a Defense drop; pretty much a guaranteed OHKO after just one switchin to Spikes and Stealth Rock. Primeape is also easy enough to force out with something like Misdreavus and force it to eat more hazard damage to get it into Zangooe's killing range. Charizard is another Pokemon that Zangoose can prey upon: it's going down to Quick Attack after Stealth Rock and a round of Life Orb recoil. Scolipede is a bit trickier since it's not quite as frail and has a bulky set that can really annoy Zangoose, but most are used up early game, and Zangoose can still manage up to 50% on it with Quick Attack.
Of course, that's not even touching upon the fact that Adamant Zangoose gets the 2HKO on absolutely every single physical wall in the tier with the exception of Metang without entry hazards. If you add entry hazards to the mix and consider that they my be switching in on attack, to be followed up with Facade, things start to get ugly. The amount of sheer power Zangoose has behind it is incredible. We are talking about a Pokemon with the equivalent of 541 Attack, with a 140 base power STAB move, with a priority move for faster threats and a 120 BP move for the Pokemon that resists its STAB. Misdreavus is walled by Zangoose if it doesn't run Foul Play, and Golurk, well, it can come in on 3 of Zangoose's moves, but takes 77-90% from Night slash if it runs 172 HP, which is easily mitigated with a few hazards or other previous damage. Haunter though is definetly still one of the best offensive checks to Zangoose :/. Adamant Zangoose still outspeeds the things it needs to (Ludicolo, Samurott, most Sawk) and, if partnered with Eelektross (which really is an amazing partner for it, as not only does it nigh guarantee the activation of Zangoose's Toxic Orb with its slow U-Turn/Volt Switch, it also punches holes in walls to the extent that Zangoose can then OHKO them, something that it really appreciates, as it doesn't like going up against a healthy wall one on one, as it then has to eat an attack). Probopass is in a similar boat: also having a very slow free sitchin move for Zangoose, but instead of softening down other walls Zangoose can then pick off it can directly trap and kill off Metang: Zangoose's only counter.
Overall, I'm glad I tried Zangoose again, as it's usage has plummeted since its glory days, but with a little tweak and a nice core to support it (I use Scolipede and Eelektross) Mangoose will not let you down. (Also try Zangoose is RU, it's even better than there than here. RU <3)