Judo/wrestling and boxing.
And I say that as a (retired) semi professional muay thai fighter.
Judo because nothing hits as hard as planet earth. Soon as the fight becomes a grappling match you can finish it, or ateast you wont panic( as much). Its also treacherous , because when we humans fight we are naturally inclined to grab our opponent so we can control him. Thats when you say ,"gotcha bytch!!".
Boxing because you can take a man out with one fast combo . Every "agreed upon fair " fight starts with a fistfight.
Muay thai(like teakwondo) does have the benefit of kicking. Kicking deadly and not on, but through the "object". Teakwondo is perhaps somewhat more about speed and agility where muay thai is more about ferocity and brute force, on a high level executed both will be extremely dangerous. On top of that muay thai does takes place in what i call " the 2nd range close combat zone" ( grappling 1st zone, fistfight 3rd ,kicking 4th).
This 2nd range is just a little closer than the most natural 3rd ,where fists are thrown .in this zone knees and elbows, especially well trained , are a game changer. Besides that, I dear you to "just wrestle "with a experienced muay thai clincher. BUT, kicking on the streets is also dangerous. When adrenalin pumps , your opponent might walk through a kick or two. He might read your tactic of kicking, and catch your kick. And then you are fecked. You might also be in environments where kicking is not advised, like a slippery dancefloor or even a wet street.
Lastly ofcourse there's mma. The issue with mma is its too diverse imo and thus takes long to specialze it. It does however resemble a real fight, which will start standing but for many reasons can be taken to the ground at any moment. Hence my reference to judo /wrestling. You dont wanna be like a fish om dry land once the fight goes to the ground. BUT, it takes tons of time and you are always kinda dependent upon the martial arts knowledge your gym has. E.g a good boxing coach will be a absolute specialist in throwing hands. He might not know how to do a submission but he does know how to 1 2 3 ko a man. A mma gym might have a ex professional mma fighter that know something about everything.
Basically every martial art is dangerous by itself. You don't wanna run into a specialist from neither arts, as they can all take you out really fast.
Still , if a complete noob would ask me this kinda controversial question, I would lecture him on how streetfights are dangerous and next tell him again; boxing and judo/wrestling .