Gosh i would've like to have done this myself, but i'm a newb like most of you and i could only just search out macros for different classes. Not sure why i didn't do this before, but anyway.
WowMacros is the perfect site to find macros for your class that are dedicated to combos, item switching, easy polymorphing and the list goes on.
Here's a list for the sites for each classes;
I'll leave this open for some time so you guys can comment and let me know if the site isn't
that great etc etc. I haven't had much time to test the macros of my classes, let alone the ones i don't play.