For maximum value, I like the elf token copy and untap + mass pump, but even if you don't have a great elf in play, the other two options can pull you out from a losing situation
The Sapphire ink card only costs two to play, and has a very weak defense of one
Wizards experimented with 'symmetric draw' with cards like Secret Rendezvous, where you and another player could both draw cards, but giving your opponent an advantage for something they could probably do themselves feels like a much bigger drawback than other colors
What gets it on the list, besides the fact that these kinds of draw effects can be very good where theyre used, is Plot
And finally Kytheon, Hero of Akros was a short-lived experiment that was meant to convert Human triggers into a no-mana-required value engine, but it turns out that his Planeswalker mode doesn't really generate value the way others do