My setup is rather simple. I don't use any addons at all, except of recount every now and then to test DPS.

Am using the mouse to move my toons. Am driving my pally, as well as mouse clicking almost all of his abilities (probably one of the reasons I usually dont run OOM with the pally, spamming tanking rotations isn't required for heroics).

Buttons 2 and 4 are my DPS spam buttons (2 different ones to deal with eclipse procs).
Button 3 is a self heal for all my casters (not using this one anymore, it used to be useful early on).
Button 5 some instant DPS spells.
Button 6 is used on my shamans to throw a heal on my tank, not used very often.
7 to 0 are slightly used, mostly a dispel/purge key, thats it.
W is my mouseover cleanse, E = judgement.
R and T are used to strafe my followers left/right.
D is assist focus (my tank), F = follow focus.
Buttons Z, X, C, V and G are used for different heals (pressing them with my left hand thumb). None of them targeted on any specific toon except of renew/greater heal on the tank. Am healing any and all AoE damage with holy nova (loving my priest). I've setup a mouseover flash heal macro for the healer, not using it very often though, holy nova is too good.
^ is my oh shit my healer pulled aggro button. Hand of Protection on my healer as well as some self heal for the priest. Used that one once so far iirc.
Well, and ALT-T for magma totems and ALT-D to pop bloodlust.

That's it, pretty straightforward.