In all honesty, even though I already put in my guess, I predict the next ATH will not be until 2020  

I fear another 2 year bitcoin hibernation period before much more amazing prices. We have lived through that 4 year cycle a few times already, I have little doubt it won't happen again.

I'm still holding though. But this time I will not have a job when it hits the 2 year low to buy all of those cheap coins.