This is an incredibly broad area, so in order to pare down the amount of content I need to cover and to help you prepare for either SCG Columbus or Mythic Championship IV this weekend, Ill focus on the Modern format
Your creature cards end up being huge role players in those decks, and getting to reanimate them by exiling one of the tokens you make incidentally is frankly absurd, especially as this can make a token on an adventure as it is
For example, if you attack with a 5/5 creature with trample and it's blocked by a 2/2 creature, you can assign 2 damage to the blocker and 3 damage to the defending player
There have been so many good cards, with some being fairly pushed
Doublestrike is rarely more than doing 4 damage but it can be and has some naughty scaling potential
The History of Retrace Retrace first appeared in Eventide , which was released in July of 2008