First, you can look at the top card of your library any time you want, so that works with things like Soothsaying and Sensei's Divining Top
Still, its hard to go wrong with a versatile charm effect, and all three of the Bant-aligned charms have their uses
(I havent actually played with this, so its possible Im overrating it, but probably not by much.) Maw of the Obzedat: This guy just makes everything a nightmare for your opponent
Combined in one character and you have a card that is quite difficult to get rid of
Other entries rely on having big creatures, the higher the power and toughness values the greater the number of cards drawn
and along with other two-for-one cards like Force of Vigor, they are some of the most powerful cards in the game: they offer instant-speed interaction for no mana