OEM always for me. I've had too many problems with non genuine inks and toners...it's not worth the headache to save a little money.
I am a hybrid shop with light signage, vehicle lettering, paper printing, business cards...ect. Same with my media and paper, I use premium products. I've found there is less down time. Even if I am running a small job of 100 color copies for someone, my machine has genuine xerox toner and 32# HP paper....no jams, no bad coloring...no problems.