BTC and ETH are more stable and safer. If you want risk more (and probably gain more) you can chose by a lot of ALT coins. I suggest you to give a look at DeepOnion.
Indeed. BTC and ETH are more stable coin that most of the altcoins, but the profit they offer is quite low unless you hold some good amount of these coins. If you want to earn more, altcoins are the best choice with good project, low value, high trading volume and low market cap.
Deeponion indeed is a good coin and I have heard quite much about it being a great privacy coin which has ability to compete monero XMR. Its highly anonymous and the transactions and payments are untraceable. More rise = more gain.