GeekFan

Here's my layout. Nothing too fancy. It works with every class/spec/role. I've tested it on everything, both 120 and leveling characters. It's got info you need, without a ton of extra. If you're a hardcore raider/PvPer, you might want more, but this will work well for everyone else. You'll need to download ElvUI to get everything up and running. There's an initialization step that's important if you decide to try out the other layouts. It'll help not leave a jumbled mess on the screen.

Recommended Addons:
Big Wigs
Little Wigs
Details
TradeSkillMaster

Included Addons:
Addon Skins
ChampionCommander
CleanBossButton
Deja Character Stats
DTBars2
GTFO
Nameplate SCT
Pawn
SharedMedia
World Quest Tracker

Thanks to Blazeflack and Benik for helping me get the installer sorted out.