Certainly not litecoin, I don't see a bright future for that coin in the long-term .

Assuming you have at least that amount of Bitcoins still fixed,
I would have some Ethereum, Monero, ZCash, VertCoin, and depending on how open to risk you are,
fill the rest with a small investment of a lot smaller coins, you're betting on the long-term anyway.

You can gain money in bitcoin in trading too (or in other crypto), but that requires time, skill and luck.