Whatever I say here that I think is the best, someone else will say there is a better one and disagree with me
There are a few you can try that are full complete UI changes.
I suppose the easiest for someone who is new would be one with an Auto-Updater.
My personal fave is ProfitUI Reborn. You can take a look at some screenshos here:-
http://www.eq2interface.com/download...tUIReborn.html
You can download the Auto-Updater here and that will intall it for you with no fuss
http://www.eq2interface.com/download...rnUpdater.html
The other popular UI is eXtremeUI and you can see that and downloadit's Auto-Updater on this page.
http://www.eq2interface.com/download...utoUpdate.html
There is also ThorUI and Fetish and they can be found by clicking the downloads button at the top and looking in the Featured Projects section.
Choose which one you like the look of, but as I said...I like ProfitUI