Lets try to leave obvious answers like Brock ending the streak off of here. For me one that comes off the top of my head is Wrestlemania 24: triple threat between Orton, Cena and HHH. Orton was one of my favorites at the time and I thought there was no way Orton walked out of there still champion. HHH had returned from his second quad tear I believe 9 months earlier at Summerslam and it looked to be culminating in a title win here and you had Cena at some of the height of his Super Cenery including the surprise Rumble win he wasn't even supposed to be in due to an injured pectoral so him winning wouldn't have been surprising neither. Orton to my pleasant surprise got the win and further established himself as one of THE guys at the time and for years to come. He would go on to lose the belt to HHH at Backlash the next PPV but him getting the win at Mania was surprising due to how Cena and HHH were being built at the time and imo solidified Ortons status at the top of the card.