Well, I put my trust in Just-dice.
Letsdice LOOKS better, but they had an IPO of 10,000 bitcoins BEFORE the site was even in real time, which I don't like.
I've joined since day one, made a few bitcents, and cashed out. I see no problems, but the owner is "Martin Gale" Which is kinda funny, lolz.
Hahaha I doubt that's his real name, but if it is then it's one hell of an epic name!