Muay thai and wrestling will stop you going to the ground and if you've done muay thai for a while they won't even get close to you... those leg kicks absolutely kill, even with a shield.
Learn Brazillian jiu jitsu and you will use your wrestling to take people to the ground just so you can have some fun (only relevant for 1v1). Bjj has changed the way I look at everything, I also do some wrestling, but I really see it as a means to getting people to the ground or stopping them taking me down. I've done boxing, the foot work will win you a street fight easily (if you're not drunk) and I've done a bit of muay thai, only enough to learn a low and mid leg kick.
At the end of the day any self defense training will probably lead you to win a fight against somebody who hasn't trained, if you do sparring, just because you learn to control your mind and body. I would probably recommend Krav Maga for somebody who is willing to kill if need be, Muay Thai and wrestling for somebody who is serious about self defense and would rather stay standing and BJJ for somebody who is a pacifist and would rather choke somebody out than KO them, or if you want to toy with them or rip their arm off