At the moment Ethereum but that can change quickly with the rising difficulty and the somewhat low prices (if you compare with all time high some weeks ago)
The Ethereum price does change quickly. It dropped from 0.027 to 0.0165, but it recovered to 0.0195 now.
I know, that's why I imposed the dangers. You can either sell your Ether as soon as you get them or you can hold and hope that the price rises (which is risky cause the price can fall too)
I mine some Ethereum, in the hope that it will rise in price. But I might sell if the price drop too fast.