Litecoin, Bitcoin, and possibly xrp.
Litecoin is much faster, cheaper to send, way undervalued, and will become scarce as institutions buy it up. It also is easier to evolve with a collaborating development team and foundation.
Bitcoin, due to being the first one and recognizable, being used as a store of value as insecurity with fiat increases, etc.
XRP because if it is adopted by banks, despite having billions of coins, could become a mainstream tool for banks, etc.
XRP is undoubtedly a popular coin and many people are investing in it. But the current obstacle to XRP is a legal issue filed by the SEC. If this problem is resolved, I think the XRP price will reach over $ 1 or even reach $ 3 which is the highest price some time ago