I'd put Hardy and maybe even Raven before Cena, due to the fact that they were such great foils for Punk. Along with that, beyond the matches, the FEUDS that Punk had with both were better than the feuds that Punk had with Cena. Yes, you could say that the storyline leading to MITB 2011 was better than any one thing Punk did with Hardy and Raven, but the case for Cena is hurt by the headache inducing feud that they had last fall (you know, the one where Punk apparently had to prove himself by beating Cena despite Punk having won every feud they've ever been in and beating him like a drum since 2011), whereas Hardy and Raven never had that stupidity infect their feuds.
History will say that Cena was Punk's greatest rival (not that it's a bad selection at all), but the feuds that shaped him into the wrestler and character that he is today probably came from facing Hardy and Raven long before MITB 2011.