Some nice theories on here and at this point a good case can (and has) been made for each of the remaining 5 candidates. If I may add one more...
By the way, who made this web site? I'll come back to that...
Here is the case for 'Red Tom'
1. Has been there since the start - would be a sign the writers had a firm plan from the beginning. No matter how many seasons the show ran they could always wrap up the story. A nice device.
2. Ticks the 'where's waldo' comment made by Heller. How many times in an episode have little comments been made about a local Sheriff has 'informed the family' or 'forwarded information' etc
3. You'd pick a established actor for those upcoming scenes where we see the RJ drop his guard and show his real self. Xander Berkley is quality. Has the right amount of potential menace in him.
4. Leftie Pigeon hater... you know the rest.
5. This web site... look at where the smiley is... he's right in the middle. next to him on the RIGHT, his right hand man: Reede Smith. To his left... his Father, Bret Stiles (20 yrs age difference). They wouldn't put the answer right in the middle of a site devoted to working out who RJ is would they... surely not :)
Let me know what you think - this is fun :)