Aang is great because almost every ship you can put him in instantly becomes top-tier.
Like:
Kataang- they literally make me cry every single time I think of them. Their love story is wonderful and genuinely heartwarming. It symbolises healing and peace for both of them and the literal world. He showed her the world and he's her biggest supporter and she always defends him and they find solace in each other because they understand what it's like to be the last of their respective kind. And they're each other's hope and just... ahhh. They're so much more than the vanilla hero gets the girl ship people paint it as. Haters stay mad or smth.
Zukaang- the symbolism? They're the actual Ying and Yang of the show! The Rozin parallels? Them standing in a vortex of rainbow fire as two dragons (the blue one like Aang's tatoos facing zuko and the other one, red like Zuko's general colour scheme facing Aang) forming a heart shape around them? Zuko was literally searching for Aang and found his redemption in Aang and Aang made him a better person and Aang is literally the only person who genuinely experienced Fire Nation culture before the war and he clearly values it and he's helping Zuko bring peace to the world and the nation...
Taang- The og tomboy x soft boy dynamic. He's literally the person that helped her free herself from her parents and Air is the element of freedom? And she teaches him when to stand firm like the Earth? And I love when they do synchronised earthbending it's so satisfying and they work so well together. Toph having lost her face in one of Aang's nightmares is also a nice parallel to Ummi and Kuruk. (One caveat though: i hate taang being used as a "get Aang out of the way" side ship to Zutara)
Sokaang- they kinda come out of left field for me but the more I think about them the more obsessed I become. It's all about a teenage boy who has been forced into a role that demanded way too much of him finally learning to trust and rely on others. It's about Sokka finally living out the childhood that he was forced to grow out of. Sokka also has such a cute bond with Momo and more importantly, Appa, Aang's animal soulmate. The fics write themselves.
Sukaang- ok, I know Suki and Aang barely interacted in the show but like Hear me out.Suki is so connected to one of Aang's past lives. And she saved Appa, which would totally bond her and Aang (genuinely distressed that this was never discussed in canon). And they both value a sense of community so much, and Aang was one of the people who inspired Suki to leave Kyoshi to help others. Plus, there could be some amazing Rangshi parallels if Suki became Aang's bodyguard instead of Zuko's, which could be very plausible.
Azulaang- I adore this ship because I genuinely think Aang could really help Azula find her redemption. Hell, he was so nice to her in The Search and she literally killed him. Plus I've already laughed about how it would absolutely kill Ozai. The mental crisis Azula would go through due to fallingin love with Aang would be hilarious, and also the guilt over everything she's done, as Aang's kindness makes her realsie she was on the wrong side this whole time. He's one of the only people who can beat her at her prime and he doesn't seem to fear her at all, which is rare for her. Aang could give her the unconditional love she so desperately craves and needs.
Maiaang- genuinely adorable to me. Other than the obvious grumpy x sunshine trope, Maiaang has a lot of potential. Mai seems to genuinely like Aang in the comics, which is really cute. I also think Aang would be able to help Mai express her more positive emotions, other than just anger. Also something about the girl who was forced to remain silent and passive her whole life learning to finally let go and allow herself to just live with the help of probably one of the most active and expressive characters of the show has me by the throat. Plus, he got along great with her lil bro!
Tyaang- They're so similar and cute and bubbly! They'd have tons of fun together and I just know Ty Lee would teach Aang some gymnastics and he really enjoy it! I think he can also find Ty Lee's chiblocking very cool, since it is essentially a great way to deal with a conflict without causing permanent damage. Very airbendery. Speaking of which, Ty Lee is also very airbendry herself. I can genuinely see her finding herself in Air Nomad culture and be excited to help revive it.
Onjaang- i just find this ship so funny because imagine being a random schoolgirl in the fire nation and not only rizzing up a demigod but rizzing that demigod up successfully. This ship can also go so many ways depending on On Ji's reaction to that random cute guy who threw a cool dance party is actually the Avatar, so it's certainly interesting.
Yuaang- the ultimate cinnamon roll x cinnamon roll ship. But more than that, there's of course the Yue becoming the Moon Spirit and Aang getting lowkey possessed by the grieving Ocean Spirit. There's Yue appearing when Aang needed her most, while he's stranded in the middle of the ocean and helping him. They both understand sacrifice and responsibility, and maybe they could comfort each other through it. Also Aang being the bridge between the spirit worlds and Yue being a Spirit could lead to a very interesting romance, depending on how much the Avatar could interact with the Moon Spirit.
Jetaang- ok, Aang was just as infatuated with Jet as Katara was, right? And I think Aang was heavily affected by Jet's actions and behaviour. Also Aang really not wanting to hurt Jet while fighting him (twice!) was really cute. And Aang helping Jet snap out of the Dai Li brainwashing could be a really cool ship moment the more you think anout it.
Teoaang- Honestly their little one sided rivalry at the beginning of the episode was really cute. And I think there could be some interesting symbolism between them. Aang symbolising the old and Teo symbolising the new. They compliment each other like that. Teo comforting Aang by showing him that the critters of the temple are still alive and well is also sweet. And Aang admitting that Teo has the spirit of an airbender is so sweet.
Kuzaang- they're adorable. I loved the comic about them. Aang calling Kuzon "Hotman" is really funny. Aang helping Kuzon make a bigger flame with airbending is also really sweet. I especially like this ship in combination with Zukaang. It's such tasty symbolism.
Aang may just be the most shippable charater of this franchise, argue with the wall. He's so filled with love I have no choice but to multiship.