10) Accumulated Knowledge/Arcane Denial/Boomerang/Brainstorm/Forbid/Force Spike/Gush/Impulse/Intuition/Stifle (Tie) If I didn't mention all of these, I'd get a lot of hate mail
Mishra's Bauble The best free spell (that isn't in the Power 9) Mishra's Bauble is a very strange card
Since players start with 40 life instead of the typical 20 in Commander, the life loss from Sylvan Library doesnt hurt as much, so this two-mana enchantment essentially draws you two extra cards every single turn
You can have one copy of Black Lotus in your main deck or sideboard in Vintage
Sticky Wurms All these huge wurms draw a lot of removal, so there are more than a few wurms that are either hard to remove, or replace themselves
Youll know whether you want Gravecrawler or Exquisite Blood, basically, and as iconic as those cards are, theyre hardly essential