Ok, so you’ve become the ruler of a small but important country. Your fictional paradise is resource rich and relatively without problems and so your subjects bend to your will and acquiesce to your whim without hint of protest. All is good, but there’s one thing that gives you the screaming squitters, and so you have it banned. Forever.
What is it?
In my Nation State there are no crunchy foods. No crisps, no apples, no pork crackling…
What won’t I find in yours?
churches
People with a stupidity quotient above 1 x standard deviation.
hypotheticals
disposable nappies
After seeing clips of “Toddlers & Tiaras” on “The Soup” I’d have to say child beauty pageants.
Did you have to watch them first?
Aston Villa
Boxing.
And wine snobs. It’s just a beverage, get over it.
Death
The practice of all pseudoscience. If it can’t be shown to work under proper scientific conditions and controls, it can’t be practiced. No more dowsing, homeopathy, reiki, applied kineseology, etc.
Organized religion.
Ban wine. Two for one. 
Candy made from styrofoam.
Vertical blinds.
Assuming we can keep banning things in our own country.
Like single answers.
What about the houses of worship of non-Christians? Those too?
Cigarette smoking.
Leggings.
They are not pants.
Since you say my people won’t protest my rule under any circumstances there’s honestly very little to nothing I would ban, since I have no fear of my position being threatened.
I am also assuming my fictional country has all the “normal” laws for the protection of society that any normal country would have (laws making murder, assault, rape et al illegal.)
I guess I would ban:
Homeschooling (public or private school would be mandatory)
Bottled water (I’d allow a vending machine exception to the rule)
Bicycles on all roads with posted speed limits > 30 mph
All forms of telemarketing
Chiropractors
The locking of one of a pair of glass doors.
Like at the 7-11.
I hate that!
There are so many things that would be banned, that its hard to write a list. First of all, its not open immigration - I personally decide who joins me on my island. Can’t let in the riff raff you know.
Not only would their be a personality test to make sure you weren’t annoying and / or stupid, but there would also be a driving test to make sure you didn’t drive to slow. On my island the speed limit is the slowest you can go.