Satoshidice 
- IS based on irrefutable mathematics that behave in an honest manner under normal conditions, sometimes bets are delayed by 24 hours giving the house the window to bruteforce a hash that will be the most beneficial, the house or anyone else that receives access to the secret list ahead of time can submit selective bets and get a significantly lower house edge.
UPDATE 31/7/13: SatoshiDice is officially a scam ladies and gentlemen! Proof:
Even though hes cashing out a made man, in a final Fuck You hes decided to force all this shareholders (yes, people bought shares in this sham) to sell at a price he sees fit. No, you cant hold long term and no you cant continue to profit under the new ownership. Too bad, read the fine print.
Of course, it wouldnt be bitcoin without a little bit scamming in the form of some insider trading

Someone bought a bunch of shares just yesterday before the announcement.
Good luck Satoshi Dice and I hope you fucking burn into the ground.
Almost anyone associated with them speaks in an intellectually appalling language and is full of unapologetic loose cannons, except Voorhees himself.