Native Ethereum acceptance on hidden-service marketplaces is rare. On this knowledge base, the marketplace that natively accepts ETH is Anubis Market.
Native vs bridged
Some marketplaces appear to accept ETH but route the deposit through a third-party conversion bridge that swaps to BTC or XMR on arrival. That is not the same thing as native acceptance — the user-visible behaviour is similar but the privacy and reliability profile is worse. Anubis generates an ETH deposit address on-site and watches the network directly.
Practicalities
Gas fees apply on the user side. Very small ETH deposits may not be economical because of network fees. Confirmation count is a few blocks for normal deposits, more for large ones; the threshold is per-account.