Or maybe I'm just jealous you worked it out and I didn't, so my comment was to troll you...
I'm giving no hints. I wouldn't spoil it for you :p
But as I was watching it I got the distinct impression, as is often the case, that the program is geared toward making you think it's any one of several people, and the writers didn't know who Red John was until it was time to reveal it. They could've picked pretty much any one of the people on Jane's list - and I wouldn't be surprised to hear early drafts had each of them as the killer before they settled on the one they did.
In such scenarios there's no point trying to guess who the killer is - as it's effectively pot luck and any suspect is as valid as the others. Tis human nature that we try to work it out, though, of course.