Biggest sites are very fair indeed, like primedice, although there are people said PD is unfair, but the proof shows PD is fair.
I think the dice is not fair because it is set on the system, so it is unlikely we will win continuously. I once played dice on a few sites and as a result most of my defeat.
So you think "fair" means that you should win more than lose? If yes, than you are wrong, because fair means that result of each bet is truly random and casino has only a slight edge over the player.