Yes, some of the favors people have talked about here have been very clever, and personal to them, and the result of a great deal of thought to make the event reflect their personalities and values. And I think that's awesome, and that the HC/GOH should
have fun with them, and feel like they add to the overall atmosphere of the event.
But if it's just like, one more thing to cross off the list--that doesn't seem like much fun to me. So many things about these events are not really required
--flowers, chair bows, centerpieces, six forks at each setting, etc.--but people get stressed about them and feel like they must
have them, even if they couldn't possibly care less otherwise and don't have much room in their budgets. If you can't think of a cool, "you" favor and you'd rather spend the money on something else, I say go for it. If you can't think of a cool favor but someone else (like a MIL) really wants/expects them and you've got room for it in your budget, I vote for a quality consumable.