I threw together a deck of mono-black legends that I believe I've never played as general.
At the beginning of the game I shuffle the deck and pick a general at random. After the game, I remove that general from the deck completely, and add a different one.
I build a lot of decks; if I build a new deck that uses of these generals, I try to remember to remove and replace it from this deck.
Click here for a text version of this decklist
Click here for my EDH Commander decks