Facts from Bruno Heller:

1. Patrick Jane is not Red John

2. "We can trust that list" (list of suspects from Season 5 finale)


Facts we know from Lorelei

1. PJ shook his hand

2. He is a man (As he had a sexual relationship with Lorelei)


Facts from Rosalind:

1. Red John is about 6 feet tall ( which means that Gale Bertram is discluded)

2. Red John has straight short hair (not the case for Sherif Thomas Mcallisar)


Discluding the other suspects:

1. Bret Stiles: a litte smaller than the average and Too old for a sexual relation with Lorelei and Rosalind

2. Ray Haffner: Would be too obvious as he is only appearing for being a suspect

3. Bob Kirkland: WAAAAAAAAAY too obvious. And when he killled at the Hospital there was no Smiley.

4. Reede Smith: Too fat which Rosalind would have mentioned.


Do you remember season 1 Episode 1? Brett Partridge seems to be Close to an orgasm when describing how " red John " killed the victims. On top of that in the season 2 finale, Jane Comes back into the room and Kind of Shocks Partridge a Little bit which Red John does to Jane for revenge after the Tigre Poem.
The voice is very Close to Partridge as we can hear at the end of seasons 2 and 4. On top of that the voice sounds nothing like an older man ( Mcallisar, Haffner, Stiles, Bertram). You could argue that the voice is tricked through the mask and the mobile phone, but the Little Girl in season 4 tells Jane that RJ has a weird voice. Therefore it fits.

In conclusion: 4 suspects can be discluded 100% 2 others are unlikely. Brett Partrige would perfectly fit the role of Red John mainly due to his behaviour in Season 1, Episode 1.
I think that at the end Jane wont but Lisbon will shoot Red John rightfully.

Except from the description details by Rosalind harker Reede Smith is the most plausible because if you switch the alphabets you would got "the red is me".

I think that it's him because he has the correct description from Rosalind Harker and the voice of red john in the last episode season 2 is very familiar to his.

Read this carefully because it will only enlight few people once.
According to Bruno Heller:

Red John IS one of the seven people on the list.

Red John is NOT Jane.

Roselind
Harker has described him as being of average height (just under 6')
with short, straight hair. He is neither strong nor weak in muscular
build. He also has rough, calloused hands.

Seems to me the only one's left are Robert Kirkland and Brett Partridge.
Both are around Jane's height of about 5' 11" (just under 6'). Both lean in build with short brown hair.

Kirkland
is almost too obvious. Plus, in another earlier
interview with Bruno Heller, he mentioned that RJ has been a sort of
Where's Waldo in scenes all the way from the very first season. Kirkland
is relatively new.
Lorelei
also told jane that she was suprised RJ and Jane didn't become life
long friends the FIRST time they shook hands. As far as I know, Partridge and Jane do not really like each other... There is no plausible way
for Lorelei to have the knowledge of Jane and Kirkland's handshake, she
was in prison and had no contact with Red John or Jane at this point in
the show. Last argument, Kirkland killed Lennon in the middle of a
hospital with witnesses everywhere (not RJ's M.O. at all). Furthermore,
Lennon didn't remember Kirland.

If
Jane is to be believed, the only one with blue eyes and every other
aspect would be Partridge from what I can see. He seems obsessed with
the Red John cases. Serial killers love to put themselves right in the middle
of their own investigations- being in forensics would certainly help
that. He bugs Jane - another win for RJ there. Plus - he's just
downright creepy. Personally, I'll have to go with Brett.