This is what I think should happen, someone like Naruto or Sasuke gets into a fight and gets the shit beat out of them. The bad guy is about to kill them when out of nowhere Lee jumps in. He says some shit about how he can never become as strong as Naruto/Sasuke but he will protect them no matter what. Then he goes crazy and starts opening all the gates. He finally opens the last gate and beats the shit out of the bad guy. In the process of doing that he fucks up his body and kills himself.
This seems like the best scenario since it will make Lee fans happy (because he goes out with a bang) and it makes Lee haters happy (he dies).