I think that it’s important to have a game-plan when you do stuff like this, an idea of what exactly you’re going to do with your newfound superpowers.
For example, say you’ve found a genie who’s going to grant you your three superpowers. That means that even before you start you’re entering a world where there are likely to be creatures infinitely more powerful than you.
Because really how could anyone think that their three wishes are the best, most effective wishes a person could make. We all know there are people out there smarter than us, and in a universe where genies or other plot-devices exist, surely some of them have been given the same opportunity as you.
So odds are that there are more powerful (even God-like) beings out there who probably aren’t going to be wanting any competition. So you’ve been given potential antagonists you know nothing about before you even start.
So in that situation, you have to be quiet. Live life relatively low-key until such time as you feel confident enough to announce yourself on the Galactic Stage.
So first things first, I’d probably wish for Immortality. None of this ‘ah, but you still age’ nonsense. Full-on Eternal Youth ™ with all the trimmings. I’d broadly categorise that as no cell death as a result of degeneration or mutation, which would allow me to live as long as I damn well please, but wouldn’t necessarily leave me immune to being hit by a bus or stabbed (more on that later).
Second power would be full metamorphosis of my own body (I’d like to extend that ability to other people’s bodies too, but I don’t want the genie thinking I’m taking the piss) so being able to transform myself into anything I want while still maintaining my full mental faculties. Because its bugger all use turning into a seagull and suddenly forgetting that you can turn back, isn’t it?
This’ll help me hide away when I need to, and probably give me a decent living all things considered. Good people will use it to turn themselves into super-heroic protectors of the innocent, while the rest of us will just seamlessly replace anyone who seems to have more power/money than they know how to use effectively.
So my first two powers basically give me effective control over the human race, because above all else I have time to spin my plans out over centuries or even millennia, while my mortal opponents wither away or lose focus.
Over the course of the next million years or so, I can purposely lift the human race up to the level I choose for it, dictating not just technological progress but social and moral progress as well. If I want people to get interested in the space program, I’ll just turn myself into a beyond cutting-edge space station, telling everyone that good ol’ NASA has been beavering away and now there’s space for 10,000 people to live in comfort and luxury above the Moon.
Want to cauterise a regressive regime that is destabilising the world’s collective peace? Suddenly key members of the government are surprisingly compliant, even obliging to the requests of the global community.
A particular religious group fomenting terror and fear in all directions?
“God turned up just outside of town! He’s 100ft tall and he keeps telling us to ‘stop raggin’ on the gays!’”
With time, tact and the occasional display of terrifying power (however much of a sham it is) will help you bring one planet begrudgingly into the future, where you can shape it to your will.
Any beings that are ‘like you’ on Earth will likely respond in fairly short order, and your ability to magically be somewhere else (or something else) will basically allow you to keep yourself safe.
But what if they just decide to carpet bomb the area, and your dumb ass pretending to be a rock just gets 'sploded?
Well that’s where wish number 3 comes in.
My third wish would be the most ‘interpretive’ of the three. I’d ask the genie (or whoever is giving me these superpowers) to give me the power to choose the date, time and method of my death.
Meaning that any attempt on my life is doomed to fail because I didn’t select that time to die.
You get bullet-proof invulnerability without having to sit on your own watching the heat-death of the universe.
If someone blows off your legs, transform yourself into someone with legs.
It’ll hurt, sure but you won’t die. And wish 2 means that you won’t be permanently crippled or taken ‘out of the game’.
This allows you immortality, invulnerability and the ability to die should you wish to do so.
Admittedly this system isn’t perfect, you could be tossed into a black hole or someone could find a way of otherwise incapacitating you, but they can’t kill or damage your mind because of that caveat in wish 2:
“…being able to transform myself into anything I want while still maintaining my full mental faculties.”
Meaning that your ‘mind’ is for all intents and purposes kept outside the physical universe, and cannot be harmed by anything inside it.