Jounin: Kakashi (great insight in battle, Sharingan, over 1000 jutsus ready to use)
Genins: Lee (great taijutsu, extremely fast, probably able to create a lot of openings for attacks)
Naruto (great stamina and chakra capacity, cause a distraction to the enemy to create openings for attacks, although a few number of jutsus, they are quite versatile, able to call upon Kyubi's chakra)
Sasuke (quite analytical, good choice of long range jutsus, Sharingan)

This seems like the team that I would choose, although each have their weak points.

Kakashi: unable to use Sharingan as much as he would want to, great number of jutsus can easily drain his chakra
Lee: unable to fight using long range, Lotus is a double-edged sword, might try to go "overboard"
Naruto: unpredictable (#1 ninja in surprising people), tends to waste stamina and chakra, might try to go "overboard"
Sasuke: not fully developed Sharingan, fire jutsus can easily be stopped against the right type of enemy, depends on Chidori a bit too much, high speed drains stamina quite quickly