For those interested in deep customization, you can even begin Getting started with writing AddOns using Lua and XML to build your own unique interface elements. If you prefer a curated experience, many players use a Community 3.3.5 Addon List to find stable, pre-tested packs.
If you want your player frame centered on the bottom of the screen with a cool cinematic look, this is the one. It was massive in 2009. wow 3.3.5 ui addons
If you don't want to spend 4 hours configuring individual mods, start here. For those interested in deep customization, you can