Emeritus of Truce The White Emeritus is the only one that can't re-prepare itself and, when revealed, was subjected to hearty guffaws about how WotC always gives white the worst toys
The same is true for first strike, double strike, deathtouch, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance
Rampaging Rendhorn Rampaging Rendhorn is by far the weakest card with riot
But you can also double up on your Selfless Spirits and Consecrated Sphinxs
Archmages Charm Archmage's Charm might rank higher without its horribly restrictive mana cost
When new cards are able to define their effects in such general terms, it allows for open-ended synergy across the whole history of Magic setting the table for both creative deck building and those memorable improvisations that can swing Limited games