wich is the best
Personally I think it depends on your own style of fighting. People have different builds and different preferences. Also the opponents choice of style could really influence what I relied on. I however generally rely on boxing and wrestling.
and what is the most affecting factor of your fighting (or sparring) perfomance?
I was always naturally strong but my stamina was generally shit. I had to work hard to get over getting tired too quickly.
and also have you ever apply your skill in any real life street fight?
Of course I have.
me myself is a silat warrior (indonesian matrial art) , and my coach command me to run about 5-6 km 3 day per week , and i think that doesn't do any shite on my body. so i just focus on sit up , back up , and plank , scout jump , and wrecking target.
I think Azure already mentioned this but stamina is some of the most important shit man. Running helps build it.