Litecoin and Ethereum are in the top ten and are both good enough to invest in longterm. I will consider to choose invest in ethereum, because ethereum is so useful in many situations. You can trade or do transactions easily with high speed, also you can invest in ICOs with ethereum. Many ico nowdays are basing on Ethereum platform so it would be better to invest in ethereum because there are so many benefits from it. So ethereum has huge potential in the future in my opinion.