I will choose litecoin and ETH. ETH is for me the best one, because it is supported by many people even blockchain has added support for ETH so you can buy btc and eth on the same online wallet.
Litecoin is also a good one for it is now sleeping and it can one day rise very high if we are lucky. I have already invested in LTC and not ETH, because i have not that much money.
I choose LTC and ETH too but with ETH I use it to invest to some ICO. just hold ETH doesn't gain much profit
I might be more amenable to etherum for a long-term investment. because etherum is still in great demand because first many ico users will certainly utilize etherum to receive their tokens and it will make etherum continue to survive and grow. unlike litecoin. I think litecoin is past its time? better looking for other potential altcoin