Okay, so here's my 2 cents.
Code:
Pokemon:
Scyther
Sneasel
Yanma
Tangela
Items:
Berry Juice
I basically echo the sentiments of Heysup as far as the initial bans go.
Scyther is basically the world's biggest crock of shit. It not only combines unparalleled dual STAB, coverage, and power, but it's also bulkier than Bronzor, one of the most defensively apt Pokemon in the game. It's even got pseudo-STAB Technician Quick Attack for those rare cases where it's not quite fast enough. As Heysup said, "it's Arceus". It excells at doing absolutely everything to the point that there's basically nothing that can compete with it... maybe not even itself.
Sneasel goes hand in hand with Scyther, except it's slightly weaker but also slightly faster. Incredible dual STAB, great power, and enough Speed to outrun the common Choice Scarf users (21 speed) without any boosts is notable. In addition, that +2 STAB Ice Shard off of Sneasel's awesome Attack is ridiculous. It may not have Scyther's bulk, but it's got the vast majority of its bullshit going for it.
Yanma is another one of those Pokemon that gets incredibly difficult to deal with if it's allowed to do, well... anything. 65/45/45 defenses aren't bad, and 75 SAtk / 95 Spe is insane, and Speed Boost just makes that doubly insane. The only real option against Yanma is priority, Munchlax, or Bronzor. Of course, Priority gets iffy, as Yanma is 4x resistant to Mach Punch, there are no STAB Bullet Punch users, Aqua Jet is neutral, and it can pack either Protect to deal with Fake Out or Hypnosis to cause major problems for Sucker Punch users. It can even use Roost if it wants, and with its high Speed and Special Attack, it can even choose to forego Speed investment and just drop those EVs into bulk, making it even harder to deal with.
Those of you who know my LC past know how I feel about
Tangela. It may seem like Sunny Day is a mediocre option sometimes, but Tangela is definitely an eye-opener. With its insane Defense stat, awesome Special Attack, and Chlorophyll, it basically needs only one turn of setup from *another* Pokemon, like Exeggcute or Bronzor or any of the other effective Sunny Day setup Pokemon to become obscene. It's impossible to outspeed even *with* a Choice Scarf, and Ice Shard is the only Priority move that's really effective against it. Between Solarbeam, Ancientpower, and Hidden Power Fire, Tangela is more than capable of punishing basically any team, and there are very few realistic checks against it. And then, of course, there's the new Sun-boosted Growth, which makes Sunny Day Tangela even better.
Finally, my opinion on
Berry Juice hasn't changed since I first playtested it. With the average HP of a Little Cup Pokemon being around 20, it basically turns the entire metagame into "ohko or 3hko". This creates an environment where the only real option is to use a setup sweeper that can OHKO opposing stuff... which becomes super easy when you factor in the fact that it's almost guaranteed to be 3HKOed at worst. On top of that, there are plenty of new nasty ways to set up, such as Shell Break, and many of the old ones are still extremely effective (DD Dratini and friends), making an item that turns the metagame into a setup-oriented clusterfuck even worse.
Now, just for my input on some other stuff, which may or may not be bannable.
Shell Break is absolutely ridiculous, and its recipients may well be too. The users are at this time:
Shellder
Omanyte
Clamperl
Ishizumai
Purotooga
Each of these Pokemon have their own special traits that make them effective. Shellder got a huge buff on top of Shell Break with the buffs to Icicle Spear (50 BP -> 125 BP) and Rock Blast (80 Acc -> 90 Acc), and it's mighty easy to set up with. Omanyte has a solid typing as well as a great special movepool, SAtk stat, and decent starting defenses. DeepSeaTooth just makes Clamperl insane, and can actually let it invest in its defenses to make it slightly bulkier, since with a +2 boost there's no way it actually "needs" the investment. Ishizumai has Sturdy, which means that if SR isn't up it's guaranteed to get the Shell Break off, and god help you if it manages to get it up AND still have full HP afterwards. Finally, Purotooga has the best Attack stat for it, great dual STAB, and not only does it also have Sturdy, it also has STAB Aqua Jet, which is absurd. It even gets Earthquake, giving it QuakeEdge coverage AND Aqua Jet's priority.