Here's mine: http://sinistral.netfirms.com/interface.jpg (copy paste, as hot linking is not allowed).
The upper bar is the Titan bar, you can add all kinds of neat stuff in there, from latency to a Defence Checker that keeps track of which places are under attack.
Under my Portrait you see a HP/MP ticker, it's a small not particulairly needed addon, but it has proved it's usefullness.
Around my World Map thinger you see alot of new icons:
CT: This is from the CT Mod, it has a core that powers all the other functions, things like a cooldown timer in the skillbutton, Bag Mods, you can change the way HP/MP is showed, in numbers/percentages, you can also change this for parties, it allows you to move just about any frame in your screen and more of those doodads.
RA: Raid Assist, part of the CT Mod, basically what it says. You can completly configure a raid setup, you can sort members by party number or class, you can set Main Tanks and Offtanks, see buffs/debuffs and anything else Raid related.
SCT: Scrolling Combat Text, shows you how much damage/healing or what skills are use against you over your head, kinda like in the FF games, it's also very usefull to quickly counter a heap of effects.
Kill Log: Keeps track of what you kill and the loot dropped, nothing big, but neat.
Atlas: The Instance Map mod, shows you routes, boss locations for instances. Quite usefull.
MonkeyBuddy: Small addon that shows you your increased speeds (mounted/travelform/otherwise) as a percentage (100% + modifier%), and more of those little doodads.
In the lower left you see a small bar saying Overall DPS, this is a DPS monitor and keeps track of the skills you used, displaying damage, crits, misses, dodges, parries. It's nice to check your skills and how well they do overall.
Underneath you see a controll bar for my skillbars, which allows you to (un)lock them so you can move them around and change the setups.
The one mod that you can't actively see is Decursive, if you look close in my skillbars you can see my macro for it. This little addon automatically uses the skills you have to cleanse Poison/Disseases/Curses/Magics that count as debuffs, but it also targets party members automatically. So all you have to do is spam the macro and it'll use the appropiate cleanse skill on a party member without having to select them.