the coins that i know is active until now is monero, bytecoin, boolberry and notes. that all coins is available in the poloniex market exchanger and if you have each of the coins with big amount, you can start to trade in poloniex and you can watch the coins movements. i don't know the other coins which in the cryptonite algorithm because i only know that coins.
By notes do you mean DigitalNotes? Monero is ofc the only real success out of these coins, although there is no doubt that ring signatures are a very useful feature. I heard about some crypto note called infinium (something like that)?
There was also dashcoin a while ago, it might be active but it was only mined on minergate and now it's worthless.