Hi.
Ethereum it is most popular blockchain at the moment, which supported by huge number of the projects. I think that more than 90% of tokens based on the ERC-20 standard. Ethereum has smart contracts.
What about Ripple?
Ripple is going nowhere, IMO. As it proves to be quite similar to traditional financial institutions (like Banks), people would think twice before investing their money in a "cryptocurrency" that's highly manipulated by bankers and the government itself. On the other hand, decentralized cryptocurrencies like Ethereum provide much more freedom over one's money, as no single entity or company would be able to freeze your account or do anything else with it. This means that if their blockchain is still alive, your money would be kept intact for many years to come.
Ethereum fits the bill quite nicely, and it not only provides a medium of exchange for anyone around the world, but it also provides access to a variety of dApps that are censorship-resistant. This is something you wouldn't see on Ripple (or should I say XRP), as its main purpose is fast, and cheap transfers around the world. Perhaps, even if XRP is centralized it could somehow become successful if Banks worldwide use it for daily transfers. But other than that, Ethereum will always prevail for said reasons, remaining as the "King of Altcoins" for a long time. Just my opinion
