I actually wrote a post about this subject in the DLC thread. I thought it would be such a cool idea to bring back three previous characters to play with the current ones separately. Franklin plays with CJ. Whose about 45 and experienced in turning a young up and coming hoodlum into a multi-millionaire. Michael plays with Tommy. They seem similar. Trevor would be a toss up, but I'm thinking Claude. It would be funny for crazy Trevor to play with Claude. He doesn't speak so it would be so hilarious to see how Trevor handles that situation. I would like this very much.
I'd like to see CJ make a return from San Andreas. He would definitely have to be older and he could still be living in Grove Street. I think it would be a nice blast from the past.
Its just got to be CJ to be honest! I would love to see how his life carried on after the last game he was in!
I think it would be cool for them to bring back CJ or Niko Bellic in a new DLC, because they actually mention Niko Bellic in GTA V when they're talking about a guy from Liberty City who "went quiet" and disappeared. I think CJ and Franklin would get along because they're both basically decent, reasonable guys who live in the same city surrounded by the same gangs.
Like others have said, Tommy Vercetti from Grand Theft Auto Vice City. He is one of my favourite Grand Theft Auto characters as I enjoy the whole mob mentality. I find that Michael does not fit the part of the mobster too much as he was he was just another bank thief. The downloadable content could have Michael get a phone call that an old buddy "Tommy" is planning on breaking out of prison and he needs the gangs help. After the infamous trio breakout Tommy in an action packed heist mission, they start to build up Tommys empire again in mafia related missions
I think you have to go with Tommy Vercetti, the classic GTA main character. I loved CJ, but I'd rather see Vercetti come back into the franchise before CJ does. You could add him into plenty of different storylines with relative ease, too.