This question I deserves a whole article of discussion, so let me give you the broad strokes
Heres the games de facto mascot on a card from 2006s EX: Holon Phantoms set, marking Pikachus only appearance on this list
Kaalia of the Vast helps you cheat big angels into play, while Kaalia, Zenith Seeker keeps your hand full by digging for more threats
Spy Kit is an artifact that costs two generic mana, has an equip cost of two generic mana, and gives the creature it's equipped to a +1/+1 boost
Here are six expert tips to help you sell faster and stand out: Tip 1: Title the card correctly and avoid vague titles or all caps
Mishra's Factory makes it so you can only spend that mana on Artifacts but, in an Artifact deck, this is insanely strong