I've posted this before, but I'll post it again. These are the only sanctioned martial arts if you want to actually know how to fight:
Striking: Boxing, kickboxing, Muay Thai, and Kyokushin Karate,
Grappling: Judo, Wrestling (Most forms), BJJ, and Sambo.
Anything beyond this list, you should take with a grain of salt. Fort example, some forms of TKD are acceptable. But other than the rare exception, or a certain technique, most "traditional" martial arts are absolute and complete garbage.
Here's a list of things to look out for:
If your gym doesn't spar, it's bullshit. Some gyms say that it's too dangerous to spar with the techniques they teach you. If this were actually the case, they shouldn't be teaching that shit in the first place. Remember what Bas Rutten said: "If you can kill someone with a technique, you can also not kill them."
If your gym has 16 year old black belts walking around, it's bullshit.
If your gym only spars, it's bullshit.
Unless your gym trains specifically for MMA, if your gym does more than two martial arts, it's probably bullshit. I'd be weary even if it's an MMA gym unless it's got a proven record.
If your gym makes you sign a long term contract (Longer than a couple of months), with no other option, it's bullshit.
Anything that has anything to do with Chi or Pressure Points is a 100% guaranteed way of getting the Chi beat out of you in an actual fight.
Finally, use some common sense. Any martial art that purports to teach actual self defense, then proceeds to teach you a flying 360 kick flip or whatever the fuck is bullshit.
Good luck on your martial arts journey. Hopefully you don't fall into bullshit.