A cryptocurrency and the network it travels on are separate choices, and the second one determines what the transfer costs and how long it takes. This is a reference for the networks that matter when paying for a subscription.
Tron
The default for stablecoin transfers and the cheapest practical option. Fees are a fraction of a cent and blocks confirm in around three seconds. Its weakness is concentration: it is a comparatively centralised chain, which matters for large holdings and not at all for a fifty dollar payment.
Ethereum
The most widely supported and the most expensive. Fees are denominated in the network's own congestion and have exceeded the price of a monthly subscription during busy periods. Use it when your exchange offers nothing else. Confirmation is typically under a minute at normal priority.
Solana
Fast and cheap, with sub-second blocks and fees well under a cent. It has a history of network halts, none recent, and the practical risk to a small payment is a delay rather than a loss. Increasingly the default where exchanges support it.
Bitcoin
Slow and moderately expensive by comparison, with ten minute blocks and fees that rise with mempool congestion. It remains the asset most people actually hold, which is why it is worth accepting despite being a poor fit for small time-sensitive payments. Exchange withdrawal fees for Bitcoin are frequently set well above the real network cost.
Layer twos and the rest
Arbitrum, Base, Polygon and Optimism all settle cheaply and quickly and are supported where the asset exists on them. The catch is support: fewer exchanges let you withdraw directly to them, and sending to the wrong one is as unrecoverable as any other chain mismatch.
The chains that need a memo
XRP, Stellar, Cosmos, Algorand, EOS, Hedera and TON route many accounts through one address, so the transfer carries a memo or tag identifying the recipient. Omitting it on those networks usually means the funds are unrecoverable. Any interface asking you to pay on one of them should show the memo requirement above the address, not below it.
Choosing
For a subscription payment, cost and speed are the only variables that matter and the security differences between these chains are irrelevant at this size. Take the cheapest network your exchange supports for the asset you hold, and check the withdrawal fee it charges before assuming which that is.