Do the toppings you add at home follow the “without consequences” rule? This is important.
No, sorry 
But hey - guilt-free bread, sauce and cheese!
Well, that’s what I expected, but I had to ask, just to make sure.
In that case, I’m going with a pizza that has lots of toppings. For variety, I can pick off selected items each time, or leave them all on sometimes, or whatever. I’m not sure just yet what they would all be, but at least sausage, onions, and green peppers.
Smart!
I’d get one of those sampler plates from a dine-in restaurant like Applebee’s.
Chocolate cake with vanilla buttercream (real butter, not shortening, and real vanilla). Lots of other things I love, but that one has never gotten old.
Steak and kidney pie
How varied can the item be? If I say lasagna, can it be italian sausage one day and florentine the next? If I say donuts, cake or raised? mix and match Winchell’s cinnamon and Dennis Par Bakery jelly? Can it be discontinued like Product-19? Involve extinct items like silphium or passenger pigeon?
Ice cream. Am I limited to one flavor? Then probably chocolate peanut butter swirl.
Nope one thing, a one time order. The thing you get the first time will be the exact thing you get subsequent times. But yes to the discontinued and extinct items.
Fresh-cooked Dungeness crab. I only get to have it once every few years, and when I get it, I never get enough. And it has to be cooked from live crab, or it’ll taste flat.
I’d be happier if it went in and then disappeared magically in transition from stomach to intestines. I don’t need all that extra poop.
Anyway, my answer would be perfectly made double-crust fruit or berry pie, light and flaky crust, not too juicy nor too dry, not too sweet. I will not be limited to one kind of pie filling, I would get tired of it too soon, and for me the perfect crust is the star of the show anyway. However I do exclude cream or custard style pies, I find them cloying.
There is this thing in my country called “chancaca”, its basically a fist sized block of pure unrefined cane sugar. Mostly used to melt into syrups for deserts, but it is the most delicious thing you could ever taste. Obviously you can’t really have too much of it or you’ll go straight into a sugar coma. I definitely abused it when I was younger, this days I’ll get a headache if I take more than a bite. No consequences? oh, you wouldn’t see me eating anything else ever.
I already eat all the fried clams I want.
Chancaca: Exploring Latin America’s Sweet Treasure
Why have I never heard of this before?!
Well that’s a major consequence from my viewpoint, why so judgmental? 
My next choice would have been unlimited chips, but how does that work without beer? So I can have unlimited chips with no adverse affects while I am drinking beer? If so, then I’m going with chips.
Honestly, my first thought was Reeses cups, but cake is a better idea! I’ll have German chocolate, please.
Pizza? Schwarzwälder Kirschtorte? Fried chicken? Peach pie? Feijoada? Decisions, decisions…
Fried clams
I was thinking that sounded a lot like piloncillo, which I was familiar with and had bought, and the article cited indicates that’s another name for the same sort of thing, just from other regions. I felt much better after knowing that.
The versions I had purchased have been cone shaped, not block shaped. But I bet the block would be much easier to go at with my microplane grater.