the 2 coins im bullish on and know will do well in 2019 and the reasons im so positive about them are :

Bittube : This is the youtube killer and did not even start its marketing campaign and already have 10,000 daily uploads and is 1% of youtubes daily uploads, the fact that the person watching the video is getting paid in bittube coins and the creator also get paid for having his video watched is only making it more attractive for people to jump on board, this is a project that is being worked on nonstop and when marketing starts in 2019 this coin is going to be a $0.50 to $1 coin (my opinion only - you dont have to agree with me)

Credits : on Friday there was a live stream by Credits (CS) that showed a 1.1 Million Transactions per second, this is the Day ETH got a major player that can leave dust to ETH in the long run, this Friday was the day Vitalik got a hart attack knowing that there is a better solution to ETH with so many partnerships its probably the one coin that has more partnerships than all other coins and those are not junk partnerships.

both coins are a low cap coins that has a lot of room to grow and they will grow, this is not a short term holding and in 2019 i can see credits in the top 10 coins and tube in the top 20 if not also a top 10 coin on CMC.