My biggest disappontment is Tierion (TNT). Well-established company that successfully launched mainnet, and it is a main competitor to better known Factom (FCT) - you can go through a comparison in this Reddit thread. Moreover, they implemented kind of maternode system which usually tends to be a factor of fundamental price increase. They have even some real business use-cases (for example Microsoft).

However, the price has declined for majority of the last two quarters except the bullish race that affected all coins. Price remains under ICO quote and I am still holding ..