I'm voting StableCoin because it actually brings something unique to the table. Quarkcoin pragmatically brings nothing new to the table other than some security features, but cryptocurrencies are already really secure so it's more or less a clone coin. And it being mentioned on a T.V. show does not give it any better fundamentals for it to be a currency.
Stablecoin will offer anonymity with mixed transactions, and will have a very steady supply because its difficulty adjusts rapidly, every 90 blocks.
Also, in reference to the recent bitcoin crash, StableCoin has performed incredibly well:
On Tuesday, December 3rd 2013, the price of Bitcoin was around 1,100 dollars. The price of StableCoin was around 12 - 13 cents.
Today, on Saturday, December 7th 2013, the price of Bitcoin, after ENORMOUS fluctuations and instability, has now settled at around 750-775. About a 30% decrease.
While almost every other altcoin's value has plummeted, what is StableCoin's value at? About 16 cents. This is at least a 25% increase. If this isn't a sign of StableCoin's future and stability, I don't know what is.
So my vote's all for StableCoin.