PrimeDice is definitely the most popular dice site. But I don't know how people define "Trusted".
I have always seen trust as how many people trust a site with their Bitcoin.
I am very sure that
https://betking.io holds on to more Bitcoin of player and investor funds than any other Bitcoin casino/dice site as we hold close to 5000 Bitcoin.
Now PrimeDice might have more than 5k Bitcoin but that is their own money and not players.
So BetKing is trusted by people to secure 5k Bitcoin so I believe that means it is the most trusted site, but it is not the most popular.
That's reasonable but to be fair, it's obvious to me that Primedice would have well over 10,000 bitcoins in investments if we offered investing. We've gotten individual offers from people wanting to invest 1000+ coins in the past which we declined.
Also as far as trust goes, we paid out an individual winner 2400 coins which is proof we would never manipulate rolls.
The fact that Primedice holds very little user funds and makes more significantly more than any site makes it by far the most trustworthy in my book. There's just no point of failure/scam.