Werewolf Pack Leader, Prosperous Innkeeper, other Portable Holes, and tokens come to mind for great targets
Jumbo Cactuar qualifies because outside of infinite life, it is a win if it connects
Its so efficient at disrupting early curves that it actually ended up banned in Standard, which is pretty funny for such a small-looking card
they just destroy everything
While it may have a pretty high mana cost and not be as powerful as the other options, its unique effect leads to interesting gameplay decisions
As such, it doesn't hurt the game of Magic that these sorts of collectables exist, because if it doesn't interest you then you can opt out, and if you're lucky enough to open one then cool, you can sell it and buy many versions of the plain game piece