Bitcoin is definetly the safest bet. With lightning, Rootkit (SmartContracts for Bitcoin) and the network effect which is has due to its popularity, it will most likely succeed from all the cryptos.
However, I think there are niches, which can be occupied by other cryptos in the long run:

1. Ethereum cant be ignored and has great minds working on it, but the uncertainty around ICOs and the probable failure of 99% ICO projects, could make Ethereum maybe a less good investment than Bitcoin
2. Icon seems to be a solid company and the Koreans probably would prefer it over Ethereum or Rootkit anyway. With rumours that Korea will allow ICOs again under strict regulatory rules, I think Icon has the best chances to take this niche.
3. TenX has a great, trustworthy Co-Founder and I believe they try to be serious with their project and will make crypto spendable for a lot of people. It is popular in Germany and the German Tax Authorities clarified, that you dont have to pay capital gain taxes on Bitcoin you spend on products or services. And I think they wont be afraid to go the way to register their token as a security, because why not?
4. NEO and Ontology seem to be very interesting to me, as they are building an interlocked network of dApps and enterprise solutions. But mostly I think NEO or better GAS will have a spike, if Hushpuppies (a CryptoKitty clone) will be released in summer (it looks great, will be on mobile devices and the NEO blockchain could prove that it can handle the network load)
5. And finally some other great projects like SONM, OMG, ADA or EOS.

But as always... if the market drops, I am like a mice starring at a snake and not moving... regretting that I didnt bought, when the pain was the greatest.