#1: concealed carry >country where I live doesn't allow concealed carry
#2: train your 100m sprint + learn prison guard deescalation techniques and maybe parkour. >ok but I really want to learn hand to hand combat for self defense
And also because it's great for keeping you in shape and pretty cool lifestyle, right?
My choices>low cost + low time choice
Boxing. In 6 months you should learn enough foorwork, distance control, good form, combinations, etc to be able to defend yourself against the majority of the population.>if you have money choice but don't want to get hit in the head
no-gi bjj. hopefully you have some accomplished wrestlers as coaches (which seems to be the norm now). if so, once you reach blue belt you'll be able to escape off the ground, submit and or subdue the majority of the population in a one on one situation, and know a few takedowns to dictate where the fight takes place. >if you have money choice + it's a good gym + your willing to train a lot or you have a longer time frame
MMA gym. not much to say, learn a little bit of everything to become a well rounded fighter standing or on the ground. >if you have money choice + you would like to keep the fight standing + it's a good gym
Muay thai. Learn distance control, learn to fight in the "phone booth" range, learn how to strike with the hardest parts of your body (knees, elbows), learn how to use your hands and feet, and learn some throws from that nasty thai clinch.