Nice list and of course I think that the "giants" Monero and ZCash will probably be around at the end of 2018 as well. At least one of them will for sure hang around, just look at BitCoin. A lot has happened in the last year but BitCoin is still the giant. A privacy "flippening" will take time.

Personally I will go for two or three of the small-mid caps that I think will grow big. Just looking back a year there were a lot of coins in the top 100 that nobody even remembers. But the promising low-mid caps have risen and are now part of the giants: Neo and Steem.

SpectreCoin is interesting but it was a small-cap in the beginning of 2017 and still haven't taken off. If it is because people haven't taken notice I just wonder what has been going on for the last year?

Of the list I am most bullish on DeepOnion and PivX. PivX because it used to be evry hyped up and popular but have somewhat sunken back. So why am I positive?! The technology behind the coin is sound, Masternodes is attractive and popularity goes up-and-down. It might be time for a PivX re-emergence.

DeepOnion I see several people have mentioned and I think then it pretty much answers itself. It is young, only six months but delivering very fast and the support is growing. It could be a tsunami that will wash over the privacy space and at the end of 2018 people might see this as one of the giants.

To recap: Monero and Zcash will still be around but maybe not much changed. DeepOnion and PivX might smash up into the top 5 privacy coins and if successful will have some very good gains.