Q:

Difference between yamero and yamete

I often hear this from animations and read it among users when making jokes on the internet, but I wonder exactly: what's the difference between yamero and yamete? 

A:

Of the two やめろ (yamero) is the bossier one.   やめて (yamete) comes across a bit softer; it's basically やめてください (yamete kudasai) minus the ください (kudasai).   やめろ (yamero) is actually the imperative form of the verb, hence the pushy sense it can give off.   
やめて (yamete) sounds like something a girl might say, but certainly isn't restricted to girls; 　やめろ (yamero) sounds like something either guys would say to each other, or someone (anyone) might say to someone who's really not getting the idea that they need to stop.