I see investment as a stable low risk term. I love block chain technology and think that if implimented properly could produce a great efficiency gains and cost reduction. Even with my bias to the technology and my liking of private transactions, all altcoins are illiquid and unstable. They would be better speculation tools, but their lack of liquidity means that when the bubble bursts you could be very rich or very poor.
I like to think that investment as separate from speculation so no I don't currently see any altcoin as an investment opportunity.
Not all altcoins wohld be worth investing because altcoins are mostly unstable and only some good for long term holding. Now that we are on bearish market and seeing how many altcoin tokens are becoming deadcoins, it simply proves that there are only some alts which are good to invest particularly those which would survive the negative market behavior at this moment. we should further wait and see which would be able to withstand the struggles.