Here is my own investment advice but not to be taken very seriously because anything can happen in crypto space...
I think the best altcoins you can invest on in crypto space are bitcoin forks, they are very responsive to bitcoin movement and their All Time High is very good too, one for thing is these coins have their halving coming this very year as well
1. Bitcoin Gold
2. Bitcoin Diamond
3. Bitcoin Cash
4. Lightening Bitcoin
5. Bitcoin Private
These coins have their use cases and they offer better performance compare to their king ( Bitcoin ) and their team are very active as well, looking at the past chart of Jan 2018 these coins ATH are massive, buying now means buying at extremely cheap price, they are jumpy, active , responsive to Bitcoin Movement and their Halving is happening this 2020 as well.
Please do not hesitate to do your own research and go through their whitepapers, these are no new projects, they have proven their existence already, thank you
Well everyone has a freedom to choose what altcoins they like to buy and hold especially in this season that the market is slowly climbing up. Most of the altcoins are green so you will have difficulties in choosing the best altcoins that will give you the best return in the long run.
Your suggestions are good but as what I have notice these are the altcoins that almost doubled it's base price in less than two months. XRP,Litecoin,BNB and Monero.