Will another cryptocurrency see the 10,000x gain like Bitcoin? Which one(s) and why?

I am sure there will be because something needs to replace Bitcoin, eventually. All tech gets replaced in the long run. However, most people will not be at the first stages of the currency where it is cheap enough to justify the risk & returns. Right now it is looking like Ethereum or Litecoin are already on the way to that path.

Ethereum has had more dramatic growth then even Bitcoin did so it is still expected to grow. But at the current price does not justify the risk. If it goes to $1000 or above (which it probably will) one would receive 4x the money back on the investment (at $250/per coin purchase). However, if you would have purchased in December you would have much more (it was $8/per coin then).

LiteCoin is still cheap, has had years of stable history and is most simply a better version of Bitcoin. If it was called Bitcoin 2 it would probably have had a lot more action then has to date : ) Many Bitcoin developers would find it easier to develop for a similar technology, rather than something entirely different (Ethereum). Now that Segwit was activated, lighting networks and smart contracts are on the short term roadmap. This makes Litecoin the most relevant alt-coin underdog. In the coming months I would not be surprised if it goes above $100/per coin. However, crypto coin markets are not logical and the entire bubble can pop at any moment.