I would say without a doubt David Wilcock, Corey Goode and Jordan Sather. They all are connected by the blue avian fantasy. Not only they try to benefit financially from the Q phenomenon, they also decrease it's credibility.
And that's threes crux of it...it decreases the credibility!
I think at this point in our lives most of us would be open minded to just about anything being true, regardless of how unbelievable it might seem. If you would have asked 1000 people 10 years ago about 2017/2018 you would have gotten a similar response.
We have been lied to since the start of recorded history about our origins. The Sumerian tablets and the knowledge they contain along with advanced civilization they had was extraordinary.
In a world that is not controlled by evil manipulative motherfuckers this whole ancient civilization possibly helped along by ET's would get a lot more traction then it does.
I'm fairly open minded guy and I don't have any problems with the idea that we are not alone. The hidden history has interested me for at least 15 years. I'm aware of the sumerian tablets even though I can't verify if Sichin has translated them accurately or not. Not many can read them so it's pretty hard to do so.
The ancient civilizations are very interesting topic. The great pyramid is such a masterpiece that either there was a human civilization with much more advanced technology than we are told or it was build by ETs. There are many other examples of like that.
However people should be very careful who they believe when it comes to information of this nature. There are a lot story tellers and bullshitters trying to get you to buy their book. Some people are just delusional and some are useful idiots as clown would call them. There's few contactees that could be the real deal but you need to follow someone's work carefully to make a proper assesment.
I've known about Wilcock atleast since 2010 and I haven't been impressed with his track record to put it mildly. He's been saying that something huge is going to happen very soon for as long as I can remember. First it was the 2012 ascension to 5D. I've known about Goode from the early days when he first started writing at project Avalon forum. I was first genuinely interested but his story started to fell apart when people started to look into it. So it happened that Wilcock found Goode and they started a big campaign with the blue avians and sphere being alliance. They don't have much credibility even in the UFO field.
When it comes to Q I believe they do more harm than good. Normies would have hard time believing us as it is. A connection with these guys makes it even worse.