This is how I see it and this doesn't jost represent physical strength but skill as well.
1. Jun {arm wrestles and beats huge dudes effortlessly}
2. Suki {amazing fighter}
3. Jet and his gaang {took out fire nation soldiers no prob and held their own against Dai Li}
4. Lo and Li {they taught Azula, nuff said}
5. Mai {great with weapons and had the guts to disobey azula as well as the courage to have tried fighting her.}
6. Ty-lee {could chi-block very well.}
7. Rough Rhinos {most of them are cool weapon expers that can sing!}
8. Yu-yan archers {just cool.}
9. Mechanist {makes cool weapons}
10. Asami
11.Equalists {were skilled I guess but relied on numbers and weapons.}
12.Lieutenent {got beat pretty easy looking back but could fight well against Korra.}
13. Zhu Li {according to Verrick and she did handle the mech suit okay in book 4}
14. Verrick {was able to improve on Hiroshi's designs, outsmarted Mako, and is just cool.}
15. Hiroshi {a genius who invents great weapons but is probably not as smart as Verrick.}
16.. Pandao {cool swordsman but didn't see much of him to judge.}
17. Those two clans from "the great divide" whose names I can recall {resourceful, quick thinking, one of them had a sword.}
18. Other Kyoshi warriors {didn't see enough to judge.}
19. Bumi II {can't really fight at all but punched a spirit so yeah.}
19. Bato {don't really remember him but he seems cool and is smart enough to roll his eyes at Sokka.}
20. Yakone {he taught Amon after losing his bending so he counts.}
21. Aunt Wu {had cool future seeing abilities.}
22. Guru Pathnik {knew chakras}
23. Zaheer {was apparently a martial arts master before Harmonic Convergence.}
24. Hakoda {better than Sokka at least, good public speaker.}
25. Ursa {killed Fire Lord for son but no fighting skills that we can see.}
26. Kya I {gave life for daughter, but didn't know she would be so dunno if it counts}
27. Yue {never liked her but she was brave I guess.}
28. Cabbage Merchent {poor guy.}
29. Sokka {I'm sorry but in spit of a few good ideas here and there, is really overated if you ask me.}
30. Hahn,Yue's betrothed {had trouble beating up Sokka, LOL! That's why he's listest as weakest and Sokka, second weakest.}
Thoughts?