My favorite is Bitcoin and Ethereum. These two coins are always the king in cryptocurrency, and they are the most worthy of long-term investment. They all give me huge profits, so I always like these two coins.
From the beginning I've only favorite coin it is Bitcoin until now, but when it become more expensive, I find other coin which enough for my money then I found Ethereum. So right now I have two favorite coins they are BTC and ETH because both are worthy, also both are good for holding and investing because they valuable and profitable. And I think this two will become more valuable when years passed by because they both have potential.