I've felt for a long time that this game needed some continuing, side missions. I want something like a bounty office, where no matter how far you are through the game they're still looking for goblin skulls. Every time you kill a goblin you get their skull or some other totem (ear, staff, goblin specific weapon), something that I can then turn in for an appropriate reward. Maybe it's a hunting lodge where you turn in pelts, or an alchemist who is looking for specific ingredients, or maybe delivery quests for an early form of postal service. Any quests that will promote exploration and player autonomy outside the MQ. If you don't want to participate, you're not missing out on anything, but you could get some rewards (gold, potions, scrolls w/e).
Some game experiences I could liken my idea to:
Red Dead Redemption -- had some static challenges that every player recieves (hunting, plant-finding, treasure finding)
KotoR -- (not sure how many will remember this) you could turn in Gaffi sticks that you picked up off of sand people on Tatooine
Fable 2/3 -- (God forbid someone mention a positive about this game on this forum) >.< Bounty hunter quests / slave rescue, Capture the prisoner quests
If anyone can link the quote I was thinking of I'd appreciate it, as I'm at work the websites I can visit are restricted. Also please share any ideas, and whether or not you like the one I've laid out.