The most widespread assets among staking providers are Atom, Tezos, IRIS, Kava, and Dash. Staking fee ranges from 0 to 50%. 0% fee provided by different platforms for the next tokens: Algorand, EOS, ICON, VeChain, IOST, Energi, Qtum, Radium, etc. While the highest fee (50%) is taken by InfStones for staking Aion.
Data was taken from Staking Rewards. Digital assets exchanges were not added to the list.