I'd say boxing would be best for building muscle, mma or wrestling or bjj to tone yourself up. Hope I helped, good luck man have fun with it.
You confuse Sports with real fighting arts that have no rules and no limitations except the person using them.
I wanted to quit goodlife since im not really liking it. But i found a gym that does mms, boxing, jiu jitsu, muay thai and wrestling. I was thinking of going there for fitness and to learn some self defense for myself. Which would be the best for defending myself if im in a fight with someone and which would be also good for weight loss/muscle gain? Im 18, 5'11 and 210 pounds. I wanted to lose some weight and becoming lean and toned.