There's no shortage of cryptocurrencies out there for investors to consider buying, but finding the best ones that could be great investments over the long haul is much harder. That's why I'm highlighting two cryptos below that are proving their usefulness: Cardano (ADA 2.03%) and Ethereum (ETH -1.01%). If you're in the market to invest in crypto, here's why you should consider these two.

Cryptocurrency logos on a dark background.

Image source: Getty Images.

1. Cardano

Cardano is the seventh-largest cryptocurrency by market cap, but that's not what makes it impressive. The Cardano blockchain, and its ADA token, are helping to create powerful decentralized apps (dApps), and this network is quickly becoming an important part of decentralized finance (DeFi). 

That's because developers can easily use Cardano's blockchain for their apps and the network is one of the fastest blockchains out there. Cardano's blockchain processes about 250 transactions per second -- compared to Ethereum's 30 -- and could eventually reach one million per second.  

In addition to its speed, Cardano's main developers, Input Output Hong Kong (IOHK), launched an app store back in September that will give users access to vetted dApps. This move could boost usage of Cardano and make the blockchain, and its cryptocurrency, even more valuable by creating a safer environment for DeFi users.

Cardano is also much more energy-efficient than Bitcoin or Ethereum, which helps the blockchain stand out from some of its competitors. Ethereum will get much more efficient soon, but even when it does, it's likely that there will still be enough demand for both of these popular blockchains to co-exist.

2. Ethereum 

The Ethereum blockchain and its Ether coin have become a fantastic investment because Ethereum is one of the most popular blockchains to develop decentralized finance systems on.

For example, the majority of marketplaces for non-fungible tokens (NFTs) are built using Ethereum. No matter what you think of NFTs and their usefulness over the long term, they are a prime example of how Ethereum's blockchain has helped create massive new DeFi markets, with NFTs growing into a $41 billion market last year.  

Ethereum has far more utility than just DeFi markets. Major banks and financial institutions have taken notice of Ethereum as well. JPMorgan, Mastercard, and UBS have all invested in Ethereum technology, and the European Investment Bank started offering digital bonds through the Ethereum blockchain last year.

Potential investors should also know that Ethereum has a large and growing developer community, which helps keep its blockchain relevant and up-to-date. Ethereum has more than 4,000 active developers every month, by far the largest of any crypto.  

Keep this in mind

While Ethereum and Cardano could make great long-term crypto investments, investors should know that owning any cryptocurrencies right now comes with a certain amount of volatility. These two cryptos have lots of potential to grow in the coming years, but investors will likely have to stomach some price swings along the way.