Fiend Hunter with Angel of Glorys Rise and a sacrifice outlet (Falkenrath Aristocrat was the best one available in Block Constructed, but Bloodthrone Vampire is a single color alternativethe dream would be to find a Human that doesnt require an additional cost) allows the deck to infinite
It gets the preference here over Arachnogenesis because elves are a much more well-supported deck than spiders, and you can certainly play both in your green tokens deck
Ethersworn Sphinx Im happy to play Ethersworn Sphinx in decks that can reliably cast it for 4 or less mana, a pretty achievable goal
The best ones are either cheap, like Sol Ring, or do something other than produce mana
Magic: The Gathering features a colorful variety of formats for gameplay, from booster draft Limited to cool constructed formats like Standard, Modern, Legacy, and certainly Commander