I don't know what do YOU think about all of those excellent characters but here is that what I think (write your opinion, sweetie x33).
Okay, he is only 12, but he fell asleep in the iceberg for 100 years, so we can add it to 12 and it will be 112 :p oh, dear math! He s crazy, don't you think so?? He rode Koi Carps! But it's a nice child, because he always want to help, yea?? He matches to Katara perfectly.
Aang's destiny. She is just MADE for him! What do you think?? Great waterbender, nice girl (she feel the need to help, just like Aang). But maybe she doesn't fit to Avatar well... Because, you know, opposites are attracting, but they are similar.
Poor Sokka - no bending. He still can fight, but benders can fight too ! So he can't be better than they (Aang, Katara, Toph..) are. I love his deep sense of humor. I accept his relationships with Suki, but maybe he matches mora to Yue?? Actually, he met Suki faster than Yue (and Suki gave him a kiss!), but in Boiling Rock he said to Zuko "My girlfriend became the Moon" (or something like that) so he thought about Yue. So, he didn't love Suki more. But if he can't be with Yue - I understand it.
Ugh, she is the best earthbender (doesn't she?), but she is only 12 (it's a pity, she was not frozen in the iceberg ;P). Metalbender! Whoaa! I love her. She's got a deep sense of humor too. But she prefers blind jokes. ;)
And here is a problem! Yep, he loves Mai! But, you know - water and fire are opposites. And i just said "opposites are attracting", so Zuko and Katara may to be together. But I think that Mai is his destiny, I am not a Zutarian (greetings for all Zutarians and Anti Zutarians ;* !). His firebending is good but he can't win with Azula without HELP. I think so.
I don't want to write more, and I do not want to bore you my opinion, probably no one is interested ;) Byezz ! ;**