I think whoever created "Good Guy Greg" did it wrong as that face doesn't go with any of those memes
http://www.quickmeme.com/Good-Guy-Greg-/popular/1/
Don't get me wrong looks better than scumbag steve, but the degraded lighting from the original image gives it a darker look and detracts from his smile thus making him more so look like some prideful COD player than a "Good Guy"
Furthermore, memes aren't just created by some uber intehweb nerds that think they know everything and try and use some stream lined method for mass production. Memes in their truest form are something that gets passed around organically not by force.
AND THERE ARE NO RULES that dictate how a meme is created or passed on