The world of board games is a rich hunting ground for ideas and game mechanics. With this in mind I task myself with the not very hard job of playing board games as much as possible, which isn't half enough.
One game mechanic that's really impressed me of late is in a board game called Colosseum (read my review here). In it you have to buy and trade performers (gladiators, horses, lions, stuff like that) in order to use them in spectacular shows. These shows have defined requirements, for instance one might require 2 gladiators, 2 horses and 2 lions. However, you don't have to have 100% of the required performers, you can have one or two missing. You take a penalty for this, but you can still progress.
You see versions of this often - you might not have to come first in a race to unlock the next or you only need half the stars to finish the game - but I especially like it applied to a shopping list criteria like this. I'll be borrowing this mechanic for sure.