You already summarising them all. Anyway, they are really good and authentic gambling site. As far as I know, all of these that you listed are trusted already not just in this forum but in the world of gambling. However, due to the fact that there are scam gambling site, we can never remove the fear that they might become also like that when future comes. But as long as they run efficiently, nothing to worry with them.
I think these ones are here to stay, they may have been in existence for quite some time and I am sure they already have a well know reputation they wouldnt want to destroy and moreover I have played on virtually all the above listed site and I am a testament of its efficiency.
Stake should be the leading site among them all, I always want to visit again after playing on the site. So many interesting games and I love how payment is made instantly, they always give me an amazing gambling experience and I would always recommend.
I think no gambling site should be trusted to last forever, they can fold up at will but you can just say that the above site has proved themselves real for a while now and we hope it continues that way for many years to come.
To pick a favorite site among them is something that would be difficult for me because my experience with them has truly been nice and I have no regret. I did a proper research before making my decision on the sites to play and it was during my research times I got to know about this. Its not a bad idea what the Op is trying to do, asking questions like this before deciding to settle with a site can avert a lot of future dangers.