Here's my newly designed UI. I based it off of Toodel's UI and then added a lot of my own style to it. I'm currently running of a 17" monitor so once I get my new monitor at Christmas, I will be re-vamping this to fit a bigger widescreen display. =D
Visible addons:
ag_UnitFrames
Chocolatebar
Omen
Skada
MikScrollingBattleText
Auditor
AtlasLoot
Bartender
Broker (uClock, Bags, CasterStats, CPU Memory, Location)
Carbonite
DBM
Fontain
Grid + GridManaBars + Clique (This allowed me to get rid of Decursive and free up more screen space)
kgPanels
OmniCC
Prat
Quartz
Satrina Buff Frame
Scorchio
simpleMinimap
StatBlock (Coords, Durability, ZoneText)
Other addons I run on my mage:
OPie (wonderful for mage portals/teleports)
RatingBuster
XLoot
TipTac
SharedMedia
Postal
FishingBuddy
Atlas
Align
Addon Control Panel
I run a couple of others as well, but there's a few that I only run on selected characters.