Jon Snow/Aegon Targaryen

So, you're the "Bastard Wolf" and "Prince that was Promised," so where are you at/going to be and, just as importantly, When are you?

Winterfell? Easy way to get made the heir and get **** on Catelyn/Cat Stark and make her into your bitch and whore while training Sansa and Arya as his devoted sluts. Could make Lyanna be alive and decide to give her son the love he hasn't had, make Lyssa Tully devoted to you, make the "Queen Bitch of the Lions" Cersei fall in love and want to be your cumdump while claiming any and all others that catch your fancy. Gain the North as an independent Kingdom or move for the Iron Throne for your birthright and gain your aunt Daenerys as a future queen. Why worry about **** with the power? You can edit away any chance of madness, defects, and ensure that no complications of birth/pregnancy occur.
Feeling particularly vindictive on the various assholes and psychos of the world? Bring Tywin's wife back and fuck her in front of the lions (maybe spare Tyrion), age up Myrcella and fuck her in front of Jaime and Cersei, fuck Cersei in public as she declares herself the queen of whores and sells out her and Jaime's crimes while making sure her punishment is forever serving you as your personal whore, bring Elia Martell back and "console" her with **** and pleasure while gaining Oberyn Martell's daughters and lover as your personal assassins while ensuring the Mountain and Pig Monster become guests of Oberyn's "Hospitality".
Question really boils down to when are you there? Just before the King arrives? Before the rebellion? After the **** of Ned so you return home?

Dorne? Why not? They're near kin to you and they don't mind bastards that much, meaning you can gain training and status there and even gain some lovers and children of your own with no one minding. Oberyn Martell's got some lovely daughters, a hot lover, and a sister that could use some help (niece too if the daughter is brought back as well).

King's Landing? Getting interesting now, why are you there? Did Jaime recognize you and decide to bring you in as a Kingsguard to protect you as a debt to your father (the real one)?
Did you go with Lord Eddard Stark instead of going to the wall as a way to get answers and ensure you father was further protected?
Did Cersei recognize you and decide if she couldn't have the bard prince, she'd have the Wolf Prince?
Are you rewriting the story and Rhaegar won the war and Lyanna is his queen with you the Prince? If so are you going to become King soon and decide to keep your mother as your queen? Or will you take your aunt as your queen? The Female Lion as your queen? The Rose? Your cousins the sand snakes? Your half sister? Your cousins of the Starks? Your "aunt" Lyssa Tully? So many choices for you to claim as your queen, but just as many to try to seduce you if you're the crown prince. Want to lead your own path and start taking Essos as your own kingdom to merge with Westeros?

Essos? Pull a Daenerys and take over city after city? Getting Missandei as your prized assistant, lover, and bedmate? Maybe take over Drogo's horde and take the females for yourself? Maybe you decide to make yourself a **** master and claim various women you find and gain an army of soldiers? How about a free sailor that goes all over the world getting treasures, women, stories, ships, and crews with Essos as your main base?

Old Valyria? Your ancestral home. Who knows what secrets lie hidden there behind the monsters that now reside there? Treasure? Weapons? Dragon Eggs? Lost Knowledge? Who knows, but with your power you can clear the area and claim the place as your new kingdom and start building alliances, followers, soldiers, concubines, slaves, and more.

Beyond the Wall? It is a free place and there's quite a few females there. You could wipe out the White Walkers and lead/help lead the Freefolk across the wall and then take the North for your own. Sure some people you knew growing up (if you grew up in the North anyway since Cat could have paid someone to put you on the other side of the Wall when you were young) could die, but hey you can edit it that those you don't want dead don't die so what harm is there really?

The West? Maybe Jaime and Cersei knew who you were when born and convinced Ned to give you to them after Tywin "conveniently" died shortly after the sacking of Kings Landing. Jaime to keep you safe and train you and Cersei for the chance to truly get the throne in the future.

The South? The Flowers were always loyal to the Dragons and despite their desires to claim the throne for themselves, Ned could at least trust them to keep you safe and make you educated. Olenna may want to use you for the advancement of her family, but she does NOT want you as an incompetent moron like her son is, lest she doom the kingdoms and her granddaughter to a life of misery and wanting to slam their own heads into the wall. While she may not pimp Margaery out to you, she certainly isn't going to tell her granddaughter not to flirt and seduce you under her sway. A little edit here and there can have Margaery as your personal whore that you can be fucking on the grand hall table with her entire family watching along with the loyal houses and no one would bat an eyelash at it. It gets better if Olenna is giving out some political help in the form of available women to get into your bed, or hell give yourself a magical boost and make Olenna young again since she was called the queen of Beauty for decades before the like of Elia Martell, Cersei Lannister, and Lyanna Stark hit puberty.

The Wall? Well that little oath doesn't matter with some editing and you can ensure Mance Rayder's forces along with Jeor Mormont's forces to cooperate and ally with each other to keep the wall defended and help the North in the War of the Five Kings. Even make sure all the Wall soldiers are loyal and obedient to Jeor to ensure no coups or oath breaking happens. Then you can go to Winterfell bringing an army to reinforce the North and "console" Lady Catelyn over the loss of Ned and then there's Yara Greyjoy to consider by repelling the Squid invasion and take her prisoner. Let's not forget Ros being able to "relieve" your stress as well. A little more editing and you got the rest of the Ironborn attacking the West to draw Tywin away and then capturing Jaime and some other worthwhile targets gets Sansa out and then an edit to ensure Arya is found fixes that and now you've got two she-wolves waiting to be trained and tamed.

Iron Islands? Maybe they got through in the rebellion and managed to get you hostage. Balon decides you got more potential and makes you into a weapon against his future enemies by training you to be a true reaver, butcher, and Ironborn. Well claiming Yara wouldn't be that hard, and then removing Balon is easy afterwards freeing you up to take the Ironborn in any direction you choose. So going pirating, raiding, reaving, and claiming salt wives as you please, could even gain some pirates and allies in the form of raiding and selling. Why not sell your services as a privateer? Pay you enough, you'll leave a company or merchant's ships alone while hitting his competitor's more and more. (Has the potential to have crossed in women of various pirates)

The North? Maybe to alleviate the pressure and problems, Ned gave you to a loyal house to raise you and you proved yourself time and again. Maybe the females of the family are eager to taste the "young wolf" themselves. Bet that made Cat mad and it could get worse if you snag women close to her.

Or maybe there's something I didn't think of?

Regardless of where, you can gain a LOT of allies for yourself. Make the House of Black and White into your personal on-call assassins by making yourself the true paragon and champion of the Many-Faced God.
Be the true champion of the Lord of Light and fuck the Red Priestesses and grow both of your powers.
Gain the Old Gods to get the North and the Wilds under your command.
Gain the different independent empires and kingdoms outside of Westeros to your side as trainers, funding, and allies and fuck their queens, princesses, priestesses, warriors, etc etc as your own (chance to cross in other items)