FromTheShire: This is stupid good even if simply played fairly, but there are multiple ways you can do things like cast this on turn 4 with enough mana floating to immediately sacrifice it to emerge one of the Ulamogs
The Big Score Associated Sets: Outlaws of Thunder Junction (technically The Big Score ) The Big Score was messy
Since Commander is a singleton format, this means Snapcaster Mage gives all of your best spells a second charge
It also does a lot at low rarities, making it a fine addition to your Sealed deck in many cases
Six As one half of the famed planeswalker duo Wrenn and Six, Six is a legendary 2/4 Treefolk for three mana with reach and the ability to recur lands straight into play from your graveyard when it attacks
Untapping during the combat step is not optimal, but for every-turn artifacts that you're looking to tap a second time, repeatable untap abilities like this are great