What is the cheapest cryptocurrency to transfer between exchanges?

As a cryptocurrency enthusiast, I'm always looking for ways to optimize my transactions. Could you elaborate on what factors determine the cheapest cryptocurrency to transfer between exchanges? Is it simply the transaction fee, or are there other variables like speed, security, and liquidity that also come into play? I'm particularly interested in learning about cryptocurrencies that offer low-cost transfers while maintaining a decent level of reliability and efficiency. Could you provide some examples of such cryptocurrencies and explain why they are considered cost-effective for cross-exchange transfers?