$ETH

* **ETH/USD:** Ethereum against the US Dollar. This is a very common fiat-to-crypto pair.

* **ETH/BTC:** Ethereum against Bitcoin. This is a fundamental pair in the crypto world, showing the relative value of the two largest cryptocurrencies.

* **ETH/USDT:** Ethereum against Tether. USDT is a stablecoin pegged to the US Dollar, offering a less volatile trading option.

* **ETH/EUR:** Ethereum against the Euro. Another popular fiat-to-crypto pair.

Many other altcoins are also traded against ETH. If you have a specific altcoin in mind, I can tell you if it's commonly paired with ETH.