Ive always loved Caith UI, but i like the older versions a lot more than the newest one... i think im using version v15 or v16, which you can find in the "Other Files" tab. Needs a little tweaking thou, and with the older version, a lot of updates :P
You could use a edited version of Tukui, they're quite different from the regular UI.
+ Using TukUI feels alot nicer, when you have LUA-coding experience, it makes it more personal, and if you dont - i can see you would have a problem with it.
There's an Ui i can recommend, and that is LUI v3.
(Im not allowed to post links, search after it on wowinterface.com)
You should try ElvUI ,for a change its minimalistic and a really nice UI overall,although my personal opinion is to always make your own UI,so that it suits you the best.