Let's indulge in a hypothetical, shall we?

In a flash of light, Princess Celestia appears. She informs you that you show great potential as a champion of Order, and that she wishes to have you as her Paladin, a knight in her service helping her bring about her perfect society.

You would be a servant under her, unable to move against her or take her place. You would belong to her body and soul, and be held up in glory for all of Equestria to see.

The terms are simple. You will live forever in this realm, as her most trusted and loyal servant and knight. You can never return home, and most importantly you cannot refuse her. You know that with your help, Celestia's paradise is assured.

In return, she can offer you one wish. You cannot use it against her in reality or spirit, and you cannot use it to escape your servitude.

So, what do you wish for?

1170678
I have a combined wish for two things:
the ability to summon anything I want with my mind
and the ability to shapeshift into any animal I feel and back to my original form at will

your rules never stated I couldn't wish for multiple things at once

1170695
I'd hoped people would catch that.

So that's your price?

1170717
indeed.

you're planning something with this...aren't you....

DON'T LIE TO ME

1170724
Might be. Might be I want to see what people would sell their souls for, were they to do it.

1170740
I think you're planning something

calling it now

For her to serve Twilight :V

1170678
Wait, wait, wait. Lemme get this straight. I can't refuse her. The moment she initiates the conversation, I'm drafted?

1170900
Yep.

1170822
Goes against her in spirit. Try again.

1170932
Well, screwed I say. Freedom is very important to me. Well, then. I want Celestia to marry Discord and remain forever faithful to him, meaning no divorce and no murder. I know it sounds like I'm using my wish against her, but honestly? If I'm supposed to be her paladin, then I should have faith that she can get along with Discord, right? I really want to see if she can do it.

1170961
Ooh, that would burn. I really like that. And failing that one?

Now when you say "I can't refuse her" ... explain?

And if this is the same Celestia that's tryin to mind-control the whole land, then my answer is "Eat shit and die."

Otherwise, I wish for unlimited wishes.
Then to be able to live forever ...
Then the ability to use magic ...
Peak human strength ...
Peak human speed ...
Peak human agility ...
Heightened reflexes ...
To not be able to feel physical pain ...

This is one long list ...

1170983
Become a zealot like Applebloom. I really would not like to be aware of what I would be doing under Celestia's name.

What is the wish I will pay for with my soul? I suppose I'd have to wish for a love that would be true and lasting.

1170678 One wish, huh? Alright. I'd wish to have freedom of choice. Yes, I'd still be in servitude to Celestia, but I'd like to be allowed to make my own decisions, based on my thought process and my morals and standards.

Either that or as much as bacon as I want. It's a tie.

1171003
You will be in service to her. You will never leave that service. It is not an option to refuse her offer.

1171260
In that case, I wish for two wishes.
1. To permenantly be as weak as humanly possible physically and magically.
2. To permanently lose my ability to speak.

Good luck trying to get me to kill off the enemy if I'm next to useless.

1171321
Think that'd go against the spirit of her bargain.

1171464
What about immunity from emotional (Cadence's magic) and Mental (The blind loyalty stuff that everyone except the Everfree is suffering from) manipulation?
In other words, even though i'm stuck following every last order, I still get to keep my own thoughts and feelings.
Does that count as going against her in spirit?

That is a hell of a situation. Most wishes are effectively neutered, particularly any selfish wishes. Any wishes against Celestia don't work... all that's lef tis spiteful wishes, or an unselfish wish, or something minor.

That being said, I wouldn't bother wishing for multiple wishes, or doing something spiteful. I would simply wish for lifelong happiness and comfort of life for the person who mattered most to me.

I'd hate my new role, mostly because I value my personal freedom, but if I have no choice, then I'd just deal with it.

Hmm,

Interesting situation I must say.

My wish would be for a city state that exists in a pocket universe.

This city state would be offered as an alternative to all creatures one month before Celestia gains "complete control". Exactly one hour before control is assumed the entrance to this pocket dimension will be closed off denying all travel to and from it.

This pocket dimension will be theoretically infinite on the inside and contain an exact copy of the landscape c.999 years after nightmare moon was defeated.

As anyone who enters this dimension will be so of their own free will Celestia should not have any objections.

You know I actually expected a question like this off you eventually.

What about having everyone everywhere in every universe/world becoming immortal and unkillable and uninjurable (so literally unable to die) as well as every universe/world becoming infinite. Everyone would just have to suck it up and get along. or die trying.

I just thought of a funny situation for this wish: a building blows up, suddenly it's raining people. Of course the only thing stopping that from being funny now is the fact that people die from that and the fact that the only thing raining would be a thin mist of blood and concrete.

I don't think the the title of this post is really an accurate summary of the question. It implies we have a choice in the matter when, really, we have none. It's not a matter of "my price" as I wouldn't have taken this deal ever. Celestia can't give me anything I would want in exchange for this; she's taken what is, arguably, my greatest asset.

However, given that I have no choice in the matter, I'd wish to live long enough to see my freedom of choice returned to me. To die as my own person is something I value highly, and I'd very much like to have that freedom returned to me in the end if not sooner.

Or maybe I'd just wish for a sharp wit, so I can be snarky and sarcastic towards her the entire time.