Add options for Minimap / HUD Customization
Options such as full minimap, simplified minimap, radial compass, or no minimap. (image is radial compass from RDO) Having the minimap always displayed on screen is useful for questing, but takes away my incentive to explore otherwise.
Additionally, add options to shrink or simplify the HUD display. A cool option could be a context-sensitive HUD, where only relative UI pops up. (ie. you take damage so your health bar shows up, your water/food is getting low so that icon is displayed until you eat) This creates options for players who want to play with more immersion.