Like most, have to have the main ones to change the UI.
Have to have:
An action bar mod
UnitFrames
Tooltip (movement and extra info)
one bag mod for inventory
Gathermate
And to round out the list of 10:
Prat
Minimap and minimap button mod
Fubar with a few informational mods
Lightheaded
Although, I'm glad they don't limit us, as I use a lot more than that
