Madaraki
A River of Pure Piranha
To be sure he didn't get as many "flashy" moments in the series the way the Benders in the Gaang did, but keep in mind that when it came to bringing down the Fire Nation airships, working the balloons, and even the Day of Black Sun, Sokka was the primary mover/engineer of all that. Other characters might've been about a hundred times more powerful, but Sokka was easily a hundred times smarter. As I see it, the only characters who had a matching/greater level of tactics knowledge were Piandao, Azula, and Iroh.I wish they gave Sokka more cool things to do in the series.
To draw an anime bridge; he's kinda like Usopp in that area: Not an inhuman powerhouse, but when he comes through for the team, he really comes through.