Best two altcoins it is Ripple and Ethereum. See the price graph and you understand everything. Their results are looking very good. As bonus my advice for you to buy some NEM coins. This will be nice experiment.
Also I like waves, neo.
Well, Good choice. But i will suggest you to go to
Ethereum first and invest more amount here.
and then go to ripple and invest 30% amount here.
These two altcoin have low transaction fee and have excellent price graph growth are excellent.