His Wrestlemania 27 victory against Rey Mysterio Jr stands out for two reasons: A. it being one of the few good matches on the card, including doing a fairly impressive delayed vertical Superplex, and B. Cody being the only relatively new guy who came out of 'Mania looking strong.
His Intercontinental Championship victory.
His short but explosive feud with Randy Orton that saw both wrestlers legitimately bloodied at least once each and (apparently) ended with an absolutely brutal street fight that required Orton to pull out all the stops to beat him.
He put in a damn good showing at the 2012 Royal Rumble, where he entered at #4 and lasted until The Big Show eliminated him. Show entered at #30.
In the World Title MITB match at Money in the Bank 2013, Cody went quite a ways in shedding the Butt Monkey status he'd gotten in recent tag matches with Sandow and in singles action. In short order, he Cross-Rhoded back-to-back opponents, gave a delayed Muscle Buster to resident WWE strongman Antonio Cesaro onto a ladder, and wiped out the competition and the Shield by pushing Dean Ambrose off a ladder to the outside. If not for his "friend" Damien Sandow's last-minute interference, Cody would've won. To top this all off, the Philly crowd was going nuts for Cody all the while.
Following on from the above incident, two weeks later on Smackdown, Cody steals Sandow's Money in the Bank briefcase and runs off with it. When Sandow calls him out on it later in the show, Cody is shown standing in front of the Gulf of Mexico with Sandow's ill-gotten prize. Sandow then chases him down and is reduced to begging as Cody threatens to dispose of it. After all of this, Cody defiantly flings the Jerkass' briefcase into the sea. Sandow's reactions were very satisfying to watch.
Let's not forget when he and Goldust ambush The Shield before their 11-on-3 elimination handicap match in revenge for their father.
October 6, 2013: At WWE Battlegrounds, in the tag team match against The Shield to decide the Rhodes family's collective fates, Cody scores what may be the greatest, and certainly most emotional, win of his entire career, pinning Seth Rollins after nailing the Cross Rhodes with goddamn authority.
October 14, 2013: Cody and Goldie hung tough with the Shield in their no-DQ WWE Tag Team title match despite being outnumbered and fought them tooth-and-nail to the very end of the match. With Goldust speared by Reigns through the barricade, that left Cody at a 3-on-1 disadvantage...until Big Show stormed through the crowd and KO'd Ambrose and Rollins in short order. Rhodes fakes out Reigns with a Disaster Kick, allowing Show to KO the Shield's muscle and Cody to pick up the pinfall and the tag titles for him and his brother, capping off their triumphant return to the WWE and dethroning the Shield in one fell swoop.