Here are my 7 suspects:
Gale Bertram: He specifically chose the sentence "reaching end of the rope" at mall at season4 finale so that Jane would understand that the real friend is not Bertram himself, but Craig. If he didn't say that sentence, Van Pelt, Hightower, Lisbon would be dead. Coincidence? I don't think so.
Judge Manchester: Remember Bertram quoted a poem by William Blake? He can't be a fool to read the poem on purpose after the famous "Tyger Tyger" thing. He must have heard it somewhere and liked it and wanted to use it. From whom did Gale hear the poem? Of course during a poker party from Judge Manchester.
Robert Kirkland: The famous Kirkland, who has been interested in Jane and RJ case for years, since Jane joined the team. To cover his mistakes, he might be trying to get as much info as he can from the team to always be a step ahead.
Walter Mashburn: Limos, connections. These require money and charm for sure, and Walter has them. He doesn't have a full time job, so he can do whatever he wants without taking much attention.
Brett Partridge: Introduced us in the pilot episode, he has the chances of being RJ. Although we know nothing about him, it is likely that the writers made us meet RJ in the first season, because you never know if the series would continue. His occurences in RJ related episodes is another interesting thing.
Ellis Mars: Oh the good old Ellis Mars. He knew there would be other killings, and was in a case there murders were about moon phases. It should be noted that Patrick's family was murdered when it was a full moon. He also gave Jane a handwritten personal business card, showing that he is interested in Jane. He was also in same town with Todd, who was a friend of RJ.
Linus Wagner: He had to kill to save thousands of kids in Africa. Timoty Carter, the fake RJ, is thought to have lived in Africa. Wagner is the only RJ copycat to survive. Also, he is in prison and hence as the best alibi to make people think he is not RJ. With connections, he might be able to get in-out easily.
These are my suspects. I don't think anyone else can be RJ, so this is my complete list. I can't have an 8th one because I can't find anyone else to add to list. If the revealed list will be different than mine, then I will think that only the names common in my list and Bruno's list can be RJ.
My feelings at the moment say that it is Linus Wagner. Timothy Carter was talking about retiring and helping children. Wagner is also helping children. And this can be the higher path RJ was talking about. Saving children, saving the future and the world. It is a good cause to die for. If you talk about RJ's identity, thousands of kids die. So your only option is to die or you become murderer of thousands of kids.
Hope you like it!