Over the years, John Cena has had his fair share of big rivalries. The likes of Brock Lesnar, Triple H and Randy Orton are all notable opponents, but there are few who managed to bring out the best in Cena like CM Punk. Both existed on opposite ends of the wrestling spectrum, which really helped bring an intense flavour to their matches. John Cena was the poster boy for WWE, possessing almost everything that Vince McMahon wants from a top star. On the flip side, CM Punk had to kick, bite and claw his way up the totem pole, dealing with some serious obstacles on the way. Punk was not a stereotypical WWE headliner, but that's partly what made his matches against Cena so special in the first place. The Summer feud between Cena and Punk in 2011 remains one of the former's finest. For Punk, he finally became established as a headliner. For Cena, Punk enabled him to show far more of his repertoire than ever before. During media interviews around this time, Cena concluded that he enjoyed working with Punk, because it forced him to up his game like never before.