Single Combat is the gold standard: it leaves everyone with a single creature or planeswalker of their choice, but wipes out everything else and prevents anyone from casting creature spells for the next turn
Instead, Wizard's says that its banning cards based on "racist depiction, text, or combination thereof." The card that has caused the most controversy is Invoke Prejudice, a blue enchantment from 1994
Karazikar, the Eye Tyrant, Marisi, Breaker of the Coil, Kardur, Doomscourge, Baeloth Barrityl, Entertainer and Firkraag, Cunning Instigator all bring out the worst in opposing creatures
The margin reality (no hype) Be realistic about profit
A foil copy of a heavily played competitive card can be worth several times the standard version
The Moment The Moment is a weird but effective take on cards like Oblivion Stone in which you have a sweeper but can choose to save some cards from it