CPU mining can still be profitable, even in 2017.
But you need to find coins that can be mined ONLY by cpus:
* no cryptonote coins, there are GPU miners for cryptonote
* no multi algo coins, obviously, multi algos means rewards get split among the different algo miners, which means CPU miners don't split 100% of rewards among themselves (would be like, ASICs get 30%, GPUs 30% and CPUs 30%, you get the idea), so not competitive. Multi algo coins are great in theory but they are just not competitive for miners.
My best pick is VRM (Verium), algo is so memory intensive you can't get anything out of a GPU. It requires a good RAM setup though to get the most out of your CPU.
Mining on my old single Xeon desktop, I get around 0.5 VRM daily (1 to 1.5 usd at current market prices).