is krav maga/ muay thai a good combo?

Yout should choose one of that and add bjj instead.

Best combo ever.

It depends on what your priority is. If it's self defence or street fighting etc, Krav Maga would be better than BJJ because it aims to not be on the ground because the ground is actually a dangerous place. That being said, it has the essential grappling. If you do BJJ you're probably wasting too much time.

You don't want to take it to the ground unless you're in an MMA 1 on 1 fight which is a controlled environment where dangerous things can happen.

So yes, Krav Maga and Muay Thai is a phenomenal combo. The best one I can think of. Krav Maga will train you to go for the light switch to turn the lights off, rather than more roundabout ways of doing it. If you're up against multiple attackers you want to take each one out as quickly as possible rather than wasting precious seconds feeling your opponent out and working your next move on them, because in that time the other attacker(s) can close in on you.

In MMA the best things are restricted because they would end the fight too quickly, such as Krav Maga's hammerfist to the back of the neck for example.

Honestly if you take krav magra that is technically all you need, it is a great mix of styles and involves its own so technically a stiking stlye like muay thai or a ground game like BJJ would be redundant. Also, be warned, most fighting contests will not allow krav maga or Savat stlyes.. krav maga. That being said, it never would hurt to have a back up style such as Muay Thai, BJJ or even Wrestling to incorporate your own personality into the already robust krav maga.

It depends on what your goal is. Krav Maga is a self defense system. It is based on disarming and nuetralizing threats. A large portion of Krav Maga is about disarming attackers who have weapons.

Muay Thai is more offensive than a system like Krav Maga. Together they would form a very effective self defense system. If you are looking for more of a MMA appropriate training I would swap Krav Maga for BJJ or wrestling. I think it depends on your goals.

The problem is, Krav Maga really went down the drain when it become commercialized in mid 90's. Now it is pretty much a joke.

Krav maga is a mixed style that has some muay thai in it. along with aikido, jiu jiu jitsu, karate, ect ect.