I seriously doubt there is a decent altcoin. Any reason that someone will provide in order to follow and buy into a project, is looking like advertisement that has no foundation.
I can't find anything solid that makes me want to follow an altcoin. Between 30,000 cryptocurrencies I don't see something that will surprise and evolve into a major player.

Bitcoin is 10 years old and there is actually nothing better happened all this time. Everything else looks like a cash-grab, full of fake news and hopes, full of invalid information about the tech, about decentralization and safety. Almost every blockchain has already been 50% attacked, Ethereum rolled-back it's own chain, Litecoin has no reason to exist, Monero perhaps had a reason but still so many problems with privacy, XRP, Stellar i can't find the reason people are still buying them. Some shitcoins had a chance to become something with all that influx of money in 2017, but devs thought it was better to re-invest all that money into private mansions and lambos instead of research and development. How do you think tech giants became the empires they are today? They allocated all profits into creating something better every year. Microsoft for example didn't pay a single dollar in dividents for the first 15 or 20 years of it's existence. All the profits were allocated in RnD. Which altcoin did the same? They all rushed to offload their billion coins and dump them on investors faces while talking about moon and taking over the economy. Such nonsense.
To conclude, I see every altcoin as overpriced by at least 10x right now and shorting all of them where it is possible into any pair available, BTC or USD.
I see all altcoins dumping 90% more at least and perhaps then we will find out who was milking them for profits in 2019 and who was actually working and has a decent product with a future.