Party Frames:
http://i.imgur.com/GoieJd6.png
Raid Frames:
http://i.imgur.com/UgNvGLK.png
Google drive of all the addons I use.
The most significant addons I use to change my user interface are the following:
Luna Unit Frames: These are the frames I use. They look great, and have a ton of intergrated features like a cast bar, click/mouseover casting, and a massive amount of configuration that you can do which I won't go into.
Here is the original post from the creator with more details.
TitanPanel: This is the bar at the top. It has a crapload of modules to use but I just throw stuff on there that I don't want littered all over the rest of my screen, including the game menu, bags, experience (Especially useful since bartender gets rid of your exp bar), and the other stuff you can see.
Bartender2: This allows you to move the bars around and stuff. Pretty straight forward, almost everyone uses it on retail.
SW_Stats: This is the damage meter in the bottom right.
SimpleMinimap: This allows you to make changes to your minimap somewhat like sexymap, but without the distracting colors. You can change the shape of the map, add or remove features, move it around, etc.
And that's about it for the interface affecting addons, the rest are QoL stuff which you can look into by google searching the name of the addon from the google docs file I provided. There's a lot of them and most of them do little things.
Hope you liked my UI and the addons!