Some medal accomplishments that can be repeated might be an interesting idea. eg -

Clear Skies - Repeatable - Not attempting an Invasion for 40 days ( while collecting daily reward )
Upgrades Auto-evasion Node - + 100 def and increase the 3% bonus to 4% - so and on forth

Another example :
Deep Meditation - Repeatable - Every completion gives you a Temple of Reflection.


Maybe we should set a limit to prevent OP. Opinion?

Limit = 1 sounds good to me.

those are terrible examples and should never be made repeatable, but there should be a couple i think, perhaps new medals that give temporary boosts. like daily quests, but medals. (make it show how many times you have done that medal, like the repeatable quests)
ie: disable a set number of enemy players (within that day, award given at last kill)
gain a reward from 2 or more base battles

The reward could either be an instant buff, or a useable artifact, with effects such as...
increase to raid chances, or raid reward
energy restores (small ones, 50-100 energy(i know dan wants people to level slower, yadda yadda, dont bring it up))
increase badges earned for a time period

those are just some first ideas, build on it if you like my thoughts.