Any pairing can work, if written well. Kataang is sweet in canon, but it's more just there than anything I feel like actively shipping. I find myself reading more Zutara fic because when it's done well, it's done very well. Kataang has enough canonical support that, I feel, it makes its shippers lazy. The good Zutara requires lots of development, lets the characters grow, and makes sure they find a way to take Aang's feelings into account.

Also, I love pairings where the guy doesn't mind his girlfriend could totally kick his ass if she wanted to.

*shakes fist at Avatar action figures*