Eternal Dragon gets you that Basic Plains under Blood Moon. I've had CounterTop board that bull shit in against me before, as well as Vial Goblins.

Edit. I've stolen games against Merfolk and Zoo before by just casting a topdecked Dragon. Sometimes against those decks, you have to sacrifice card advantage to stay alive. Topdecking Dragon is one of the few things that are helpful in turning the game around when you and your opponent are having topdeck wars.