Have you honestly not heard about Darkcoin?!
The media is referring to it as the new "King of Alt-coins", and it has boomed in the last few months. It went from being worth pennies to now standing at over $11.21 USD per 1 DRK. It's market cap now exceeds $51,089,687.00 USD and it is the 4th largest crypto-currency by market cap. Check out the market cap comparison here:
https://coinmarketcap.com/
You can trade Darkcoin at Poloniex, MintPal, Cryptsy and various other exchanges. You can also trade DRK with people here at these forums, Darkcointalk.org and other crypto-currency forums/communities...
And yes, of course, you can buy whatever you want with DRK. Before long, DRK is likely to become the #1 currency of choice for dark exchanges and anonymous/private transactions. And albeit controversial, it is likely that markets like Silk Road and its brethren will be jumping on the DRK train before long. I expect that this huge influx of fresh capital, and Darkcoin's position as a potential on-ramp/off-ramp for covert crypto-transactions will make its value increase exponentially.
IMHO, Darkcoin is the ONLY alt-coin with a real future ahead of it... I may get flamed for saying this, but so be it... The 100,001+ clone-coins are all going to die an agonizing death (Litecoin too), and the only ones left standing will be Bitcoin, Darkcoin and the few "elite" alt-coins that manage to offer SOME sort of tangible innovation/advantage...
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EDIT: We should actually take this discussion over to the Alternative Cryptocurrencies section where it belongs though. This deal was successfully closed. A debate about Darkcoin vs. XXXX or an open discussion of alt-coins will just annoy everyone in the Currency Exchange and be counter-productive. I'll actually start a new Darkcoin-related thread in Alternative Cryptocurrencies section in just a moment...