If there's one thing I've learned about this show from watching six years, it's that there were always logical and interesting reason as to who the killer is in each episode.  Take a look at episode five of this year, "The Red Tattoo".  That episode had a truly unique and very cool answer for who killed who, and in the end, the answer was very logical.  The answer to who Red John is would also be very logical.

Based on six years of Red John evidence, who is the most logical choice for Red John?  I vote the Sheriff for the following reasons.

1.)  The Hunter Ethos:  The Sheriff loves to hunt, loves to kill.  We all know Red John loves to kill...

2.)  Mobility:  Most of the suspects are pretty confined by their jobs, but a Sheriff in wine country has much more freedom.  They spend many hours alone with no one around.  Plenty of chances to commit murders.

3.)  Unsuspecting:  No one ever thinks a Sheriff's vehicle might contain a serial killer.

4.)  Location, location, location:  There's not much out in Napa Valley wine country, and that's the point.  It's out of the way and a great place to hide.

5,)  The Profile:  He fits the profile to a tee except for his hair.  For that there's a simple explanation.  He lost it over the past six years.  I know for a fact that the actor, Xander Berkeley had much more hair six years ago when he was cast.  I've seen pictures of him on Nikita and he still had enough hair to be defined as short and straight.

6.)  Tiger, Tiger:  Of the three suspects with a tattoo, the Sheriff seems an odd choice to be a member of "Tiger, Tiger".  He doesn't really bring anything to the table.  He has very little jurisdictional prowess.  However, if you are Red John, you wouldn't want a job that is high profile.  You would prefer to stay in the shadows and rather have your friends be powerful. 

7.)  Ornithophobia:  Although Sophie Miller thought Jay Roth lied about the kind of phobia, she believed he did have an actual phobia.  The Sheriff has a fear of birds.  One flew by him in the Church in episode 3.  He panicked and stated, "Didn't see that coming!  I hate those things!"

8.)  He Is Mar/ked:  We knew Renfrew tried to write something on his bathroom wall when he was dying.  He Is Mar could easily be He Is Marked.  It would definitely confirm that Red John is one of the three with a tattoo.

9.)  Process of Elimination:  None of the other suspects fits the evidence properly save for Ray Haffner, and he does not have the tattoo.

10.)  I'll call you "Tom" then:  RJ usually kills anyone who poses a threat to him, but not Patrick Jane.  He likes him too much.  He has tried to befriend him with Lorelei and refused to kill him when the 7 suspects were revealed.  Who is the only suspect who really appears to like Jane?  Sheriff "Tom" McAllister.  AND he always calls Jane by his first name, Patrick!

As all you who are up to date will know, the only three suspects as shown by heir tattoos are the sherriff, the fat cop and the head of the CBI. Out of these three, the only plausible option is that it is the Sherriff; he is tall like his blind lover is, obstinant and doesnt follow instructions like Patrick (when he ignores what Patrick says and saves him on the roof of the church) like Lorelei says etc etc etc...
Bruno Heller said that the real Red John is deffos one of the seven, which has now been whittled down to three, and as the psychiatrist said he is of medium build (so fat man cop out of the picture) and I think that if Ray was Red John, and he wanted to bug the CBI office all he would have to do was stay late when everyone had gone home...

So Sherriff all the way, but I reckon Bob Kirklands twin bro will pop up soon...I think he was mentioned for a reason...

Finally, they are cleaning up at IMDB!:D They are slowly removing all the weirdos from the list!:P

This might mean nothing, but I tweeted Nick Nordella, who is the "young man" in the Red John episode saying that I thought he will play the young Red John/young McAllister and he 'favourited' it.:P Of course this doesn't mean anything, but still..:)

Also, people from New York, Jack Plotnick will be in the musical Disaster from today for a month, go see him if you can! I would love to go, but I'm from Europe.:(

Let's think about who would have wanted to bug the office, I think it's very important.

1. Bertram is out, he could have bugged it himself anytime.
2. Haffner is out, he was in the office a couple of times in that episode, could have done it himself.
3. Reede Smith: I refuse to believe this nobody is Red John, if he is, this show will have the lamest         ending in the history of TV shows. He is a random stranger who nobody's ever heard of before season   five.
4. Stiles could have done it, but let's be honest..He is almost 80, he is dying, the FBI is looking for   him...It just doesn't look like it's going to be him.
5. Sheriff: He could have done it.

What we learn from this is: Whoever Red John is, the other tigers don't know. Because if the sheriff is Red John and the others know, he could have asked Bertram to bug the office, no need to bring in a silly private detective. (same for Smith)

So I think it's either the sheriff, or someone we think is dead or not on the list.
It cannot be Bertram or Haffner, they could have bugged the office themselves. For me it also can't be Stiles and Smith for the reasons I mentioned above.

It's the sheriff, or someone "dead" or a person not from the list.

I can't help but to keep going back to what Patrick said on the tv show that got red john to kill his family because he just killed his family not him something he said was right he said lives in a single story blue house with a citrus tree out front and I've watched fire and brimstone three times and keep coming back to the scene where Patrick sends a text to McAllister and he is walking out of the Napa valley blue oak substation the sign is clear in the shot so is his cop car out front that says Napa valley. If you have watched the show you know when they give these readings they are never exact but in a round about way the description is somewhat right that's what makes it seem psychic it may be nothing but who knows the diner Lisbon met gaff er in was called the reyn diner. Just seeing if anyone else has noticed stuff like this because this is the type of things that are hidden in plain sight.

In my previous theory I chose Thomas because of the telephone conversation between him and PJ at episode 3 of season 6. He said "Hello Patrick" with the exact same manner and a somewhat lower voice like the Red John phonecall in episode 1.  After the phonecall he sneaked upon PJ in the woods, PJ said "I didn't hear you coming.." Thomas replied with" I love to hunt things with faces". 
Sounds like the m.o of Red John, everytime he leaves behind a face and the last time he painted the face on Teresa Lisbon face.

What I liked the most was in episode 6 when PJ brought all the suspects together, he asked everyone to lower their sleeves. The only one who got quite scared was Thomas. He immediately reacted with: "Patrick it's not what you think." Not because he is anxious about Patrick but more that he is going to lose his friend PJ now. Maybe Thomas somehow got into the TygerTyger group for resources.