Well I believe in the top coinmarketcap surely they are good for long term investment but the best altcoin to invest for me is ethereum, you should include eth in the list.
I'm fond of investing in ETH, and ETH is my favourite coin. Like every ETH lover l believe that ETH will rise up more in the near future, it will not take a long time to see it. No doubt as you mentioned investing in top altcoins is always profitable, they are absolutely superb for investing long-term. It would be better if we saw ETH include this list.