I think Ray will have the most consistent year but I predict Paul (assuming - and I think he will - he avoids the injury big contrary to last season) will have the biggest year. Returning from an injury-plagued season, being labeled "old", "already broken down", etc, Paul will have a very strong "comeback" season in my opinion.
I expect Rondo to improve his game but not necessarily to have the biggest year in terms of stats and big games/memorable performances. But maybe we're just used to Rondo's awesomeness now so we're kind of expecting it as a given.