Which altcoins do you think will see year 2020 with prosperity and why they will survive?
I think following will be there
1) Ripple / because of its application in banking use
2) Ether / because its smart contracts and scripting functionality
3) Dash / Instant send and private send
Ripple isn't really used by banks, only their blockchain is used but not the currency, so I think it will die out in the long term. I think Ether has the most potential of the three you listed, its not only the first coin with smart contracts but its already linked to multiple other tokens that were created on it which all have value.
Finally I think in 2020 coins that have not even been released will win out, the innovation in the cryptoworld will continue and while several coins we see now will be big the best and biggest ones will be the newcomers that really improve upon the world.