Jose Iglesias hasn't been on the team for 3 years. Xander has turned into an above average fielder. Jose doesn't come close to Cander's hit tools. Also, I don't remember anyone ever calling him Iggy Pop.
If they kept Manny, he wouldn't have hit .400 down the stretch the way he did for LA. He just didn't want to be here and was fine with sulking. Thinking otherwise is revisionist history. Plus, they filled his spot with Jason Bay who played better than Manny had for the Sox that year.
These are definitely the top 2. It's beyond the scope of this post, but they should have also retained Roger and Boggs for the remainder of their careers.