Who would be the top 3 free agents for the Celtics to sign and the 3 most likely to sign?

Only 5 guys on the roster right now: J. O'Neal, Garnett, Pierce, Rondo, and Bradley with Ray Allen saying he is going to come back. There are some big names on the market, but which 3 would be the best talent for the Celtics to go after and which 3 are actually the most likely to sign there?