In 2020 i assume Chainlink and Cardano... I like VET too.
Chainlink is good to pick for me, because this coin did very well in 2019, and in this year LINK coin price can get double from the current price! But I am very disappointed on Cardano, such an unprofitable coin it is! No one knows which coin gonna rock the board and I think every good altcoin have the chance in 2020!