To be honest, I'd rather see nothing banned. There are some thoughts that I want to post.
1. I think a lot of us came into this metagame treating it as though we could treat it as Gen IV. Both are obviously entirely different metagames, so we can't quite treat them the same. New threats have risen and old ones have died off. Keep this in mind, we're still dealing with a metagame in it's infancy until we get tiering sorted.
2. Thoughts on banning something: Bans should only be made if it's healthy for a competitive environment. I've always argued that a ban must be able to be enforced, well-defined, and warranted. The first two can be done easily, as we can force a ban with a simple clause and the Pokemon/Ability can be identified easily. It also has to be completely defined, which is simple enough for an RPG. The problem is whether or not these bans are warranted, or needed.
First and foremost, if a Pokemon works well against a certain playstyle, that does NOT necessarily mean it's overpowered and in need of a ban. Take Reuniclus as an example. While being able to work excellently against Stall by virtue of Magic Guard or offense with a Trick Room set (but unable to break both), he's still stoppable. While Psychic is nice for stopping Fighting-type moves, it really has no great set of resistances to work with, and a metric ton of weaknesses that can be abused easily. Scizor and Tyranitar can kill the damn thing easily enough through moves like Crunch and U-turn, yet even outside that, both are still extremely useful, like Scizor working as an excellent scout/revenger, while Tyranitar can act as a hole puncher with Choice Band, set Stealth Rock, bait in Gliscor and Scizor for a OHKO, etc.
Moving along, minor bugs or changes in gameplay don't necessarily warrant a ban either. Case in point, these so-called "weather wars" we see a lot of, where most teams carry a weather changer. I personally like to see it as an element of gameplay to add to the mix. This has created an interesting dynamic to see who can really protect their own weather changer better, etc. While some may or may not agree with Aldaron's proposal, that ban may have been warranted since it overcentralized the metagame to where you needed a weather changer of your own or you'd die to that painful SwSw+Drizzle combo.
Still, if something seems slightly powerful, just keep playing, since chances are, 99% of the time, a certain tactic or Pokemon will have counters to it. Exceptions do exist, and those fully warrant a ban if it means a healthier and more diverse metagame. Case in point: Pre-Platinum Garchomp, where matches degenerated to teams of Garchomp, Garchomp counter, counter-counter, counter-counter-counter, etc. If a tactic overcentralizes to that extent, then there's an uncounterable argument for a banning. This example goes somewhat hand-in-hand with arguing that bans for being "too good" should only be made if it overcentralizes the metagame to the exclusion of EVERY OTHER TACTIC.
My thoughts on the bans we've made overall: I think we moved just a bit too quickly with banning things. The bans on the cover legendaries and such are completely justified as they were purposefully overpowered, like Akuma from SFII. I personally feel we made too many bans when the metagame was in a chaotic stage, even while in it's infancy.
And just because a tactic works well against your precious playstyle does not mean it's broken. Nothing says that stall or offense has to thrive, there's no defined rule for such a thing. Just a general thought.
As for things I'd love to see go, the only thing I could really make an argument for is Garchomp and Deoxys-S. Everything else is fine. I'll expand on this in a later post.
Interesting take on Deoxys-D. Most of the time, Deo-S really doesn't need its speed to get the job done, since slower offensive powerhouses are more liable to switch in on it the first chance they get. If we get rid of Deoxys-S, Deoxys-D will probably come right behind him and run the same sets with the added bonus of taking longer to die. We'll have to see about that one in the event Deo-S leaves.
To be fair though, Deoxys-S has that insane speed stat, outspeeding even base 100 scarfers of all things, and Taunt shuts down Deoxys-D, as most things that outspeed with Taunt can set up on him. The extra bulk just might not help if your offensive movepool is limited by virtue of base 70 offensive stats alongside not having the room to invest because of 50 Base HP. 160 base defenses is amazing, but 50 HP just isn't great for a support Pokemon, especially with his typing.