Woo hoo here we go lets see what people come up with...
Me I only want 3 for sure
1. BAG MOD!!! with search feature because wowzeeeeer I never realized how annoying all those bag all over my screen really were.
2. Unit frame mod or name plate mod... I could stand the Rift standard ones, if I could have some decent viewable frame with some sort of threat information out in the game world.
3. I'm going to be making a bag mod, first priority, and the reason I'm going to re-up sub for rift. My addiction to creating/modding my UI put me back to wow