I make it to be Patrick himself. He does not know it tho, Red john is the stronger side of his personality split or maybe they might go for possession giving Patrick the gift he thinks no one can have.
The red john sign on the walls kinda looks like Patrick with the slanted eyes and the top of the circle creates goes off in the same direction as his.
Also this shows how he is always one step ahead and can read patricks mind.
Red johns words at the end of s5, I will kill until you catch me or I catch you. Is one and the same thing.

Guys check out this comic i saw on the net. The spelling is that way on purpose but it is english lol

http://www.trolino.com/image?id=105963.jpg

Jane is smarter than the seven on the list . and in redjohn rules when rj kill the happy memory of jane nobody on the list is smart enough to that .and in redmoon s3  e9 todd johnoson  was helping in the case and he was the serial killer and he refused to talk to anyone else and he want to talk to jane because he told lisbon that they have connection and i think the connection is that both are serial killers helping in their cases just to distract the cops . and jane maybe have Schizophrenia so he could have two personlties one is rj and the other is someone whose want to catch rj and kill him .

I huv reasons to say RJ and PJ is one person although Bruno Heller always 
 says isn't he ?1-I think Jane after death of his wife and daughter developed some sort of mental disease what we called shizophrenia. Huv two separate personalities kind one and violent one2-he hallucinated about his dead daughter its auditory hallucinations its positive symptomplus visual hallucinations 3-  the episode when agent darsi said to him an important question if ur an enemy of red john why he didnt kill you4-when agent darsi re opend old case panzer murder no body knows that except Wainwright so how red John know and send someone to follow her

Why i am confused 

How can patrick go through hundreds of suspects and know only 7 of them could be RJ?
Sorry, but I just don't think that is realistic.

I know heller said that jane isnt RJ, which I agree. Patrick jane is the character we all love. Red John is Janes other personality, which is nothing like Patrick. Thats why heller says patrick isn't RJ.

The voice of RJ in the season 4 finale is obvioulsy Patricks. http://www.youtube.com/watch?v=l_CK_90hei0

And I don't think RJ is psychic. 

I don't think it's one of these list ...
I'm still pretty sure that it can be Patrick !

I watched an old episode today where Agent Susan darcy was investigating the death of the other serial killer(the one manipulated by patrick so RJ would kill him). She only confided in Patrick and teresa that she was pursuing the killer. Then RJ stalked her and sent a video to the CBI. Doesn't this raise questions as to how RJ found out she was pursuing the case? She only confided in patrick and teresa so how on earth did RJ find that out!? This is way too fishy so im assuming that Patrick is either RJ or Teresa is an informant to RJ.