Someone with more time on their hands who is better at math can run some actual numbers, but the loose ideas are enough for us today
For value, OP-11: A Fist of Divine Speed offers the best risk-to-reward ratio at near-MSRP pricing with high-ceiling chase cards
Hold [R], [L], then [Select] (in that order), and press [A] repeatedly while holding those buttons until it is your turn
This allows it to be activated in response to an opponent's Effect Veiler or Infinite Impermanence to take the targeted monster off the board before either can resolve
The gist of it is two players duel each other with a deck of cards that consist of Monster, Spell, and Trap cards to defeat the opponent's monsters and bring their Life Points down to 0
[c]Niv-Mizzet, Parun[/c] is a very popular commander because he has an infinite combo with [c]Curiosity[/c]