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.
I think that long term investing in alts is a very risky strategy, with the large majority destined for failure, but if you're savvy enough to pick out only the best alts then the potential returns will be mindblowing. It's as many have mentioned before, a similar situation to the introduction of the internet.