It gets silly with Narcolepsy because that enchantment taps the enchanted creature each turn
All that while filling your graveyard for other purposes, like reanimator, or while looting to your hearts content
Honorable Mention #1: Assault Intercessor Putting Massacre Wurms second ability onto a much cheaper creature means Assault Intercessor is going to make a splash
Let's say you're playing against control in Standard and really need to resolve a Chandra, Torch of Defiance

Ambrosia Whiteheart Apothecary White Bringer of the White Dawn Circle of Protection: White Elrond of the White Council Flowering of the White Tree Gandalf the White Gandalf, White Rider Gather the White Lotus Knight of the White Orchid Minwu, White Mage Nine-Tail White Fox Order of Whiteclay Order of the White Shield Rosa, Resolute White Mage Rune of Protection: White Sacred White Deer Saruman the White Saruman, the White Hand The Destined White Mage Uglk of the White Hand White Auracite White Dragon White Glove Gourmand White Knight White Lotus Hideout White Lotus Reinforcements White Lotus Tile White Mage's Staff White Mana Battery White Orchid Phantom White Plume Adventurer White Scarab White Shield Crusader White Sun's Twilight White Sun's Zenith White Tiger, Amulet Keeper White Tiger, Ava Ayala White Ward White Widow, Free Agent White Widow, Yelena Belova Whitemane Lion Whiteout Whitesun's Passage Whitewater Naiads

I love it, and best of all, Im sure were not even close to fully using the design space around MDFCs