There's no denying that meme tokens have been some of the best-performing cryptocurrencies of the year. For example, Shiba Inu (SHIB 1.98%) is up 175% for the year, while Dogecoin (DOGE 3.71%) is up 65%.

But that still doesn't make them high-quality, long-term investments. Instead of investing in highly speculative, dog-themed meme coins, it could be far more profitable to seek out low-cost, high-upside cryptos that have not yet been discovered yet. With that in mind, here are four cryptos that should be on your radar.

Crypto tokens piggybacking on Ethereum's success

The starting point for finding a low-cost, high-upside crypto comes from the Ethereum (ETH 2.02%) blockchain ecosystem, which has been attracting a lot of attention from investors this year. The latest catalyst for Ethereum is a brand-new tech upgrade known as Dencun, which could help to drive its next round of growth.

My top picks here are Arbitrum (ARB 1.85%) and Optimism (OP 2.13%), both of which are Layer 2 scaling solutions for Ethereum. What this means in everyday terms is that Arbitrum and Optimism are blockchains sitting on top of the core Ethereum blockchain, helping it to run faster, cheaper, and better.

And these Layer 2 scaling solutions are exactly what the new Dencun upgrade is supposed to help with the most. Dencun focuses on making it cheaper and faster for Layer 2 solutions to process transactions. According to the latest transaction data from crypto analytics firm Dune, transaction costs for both Arbitrum and Optimism have already dropped significantly after the Dencun upgrade on March 13.

The big picture here is that Ethereum seems to be banking more of its future on these Layer 2s. And that can only mean good things for the future value of these Layer 2 solutions. Granted, the Layer 2 sector is getting very crowded these days. However, Arbitrum is trading for only $1.75, and Optimism is trading for just over $3.50, making them relatively inexpensive ways to piggyback on the future growth of Ethereum.

A new breakout blockchain competitor

Given Ethereum's success, there continue to be new blockchain rivals that are attempting to supplant it as the premier Layer 1 blockchain in the world. So if you aren't sold on the idea of Ethereum as a high-growth blockchain and are skeptical about the value of Layer 2 scaling solutions, you absolutely need to be aware of Sui (SUI 2.63%), a relatively new Layer 1 blockchain.

Investor with laptop sitting on steps.

Image source: Getty Images.

The Sui team is led by former blockchain developers at Meta Platforms (META -0.59%), making this a high-profile new entrant in the Layer 1 blockchain niche. Remember when Facebook was trying to launch Diem, a new digital currency? Well, that was just one of the projects that members of the Sui team formerly worked on when they were at Meta. Sui has been described as a potential "Solana (SOL 5.47%) killer" for its high-growth upside and ability to take on the biggest Layer 1 blockchains.

Just keep in mind, though, that just having world-class talent on board doesn't guarantee a winner. Just think of your favorite sports team -- even with top draft picks, splashy free agent signings, and a core group of veterans, a team can still fail.

That said, just about everyone agrees that the Sui blockchain is faster and more secure and scalable than originally anticipated, and that could be a huge edge in eventually winning market share away from rivals.

Best of all, Sui is still super cheap. It currently trades for just $1.75, giving the crypto a $2 billion market cap. That's pretty impressive, given that Sui only launched last year.

The best AI crypto token

Finally, there's Fetch (FET 3.55%), an AI crypto token with a robust $2.4 billion market cap. This is one of the crypto tokens that has benefited the most from all the hype and speculation around artificial intelligence (AI) and ChatGPT, and for good reason.

Fetch, founded by a world-class team of AI researchers in the U.K., is attempting to create a global platform for the AI economy. Their current project is a marketplace for paid AI bots, similar to the ChatGPT Store that launched in January.

Of course, artificial intelligence is still in the early innings, and it's almost impossible to predict which AI crypto tokens will have the most long-term staying power. Thus, while I'm extraordinarily bullish on the future of AI, trying to pick a winner among dozens of new AI crypto tokens comes with a high degree of risk. So buyer beware.

Reasons to forget about meme coins

It's time to forget about dog-themed meme coins. There are just so many super-cheap, high-upside cryptos out there that are better alternatives.

I've picked out four cryptos, all trading for less than $4. All of them have market caps of $2 billion or more, and all come with impressive growth catalysts and real-world use cases. Yes, they aren't household names (yet) but I view them as superior long-term plays than dog-themed meme coins, which in my opinion, are all bark and no bite.