3. Blake Lively and Penn Badgley
Before Blake and Ryan, there was Blake and Penn, aka Dan and Serena from Gossip Girl. To put it lightly, fans freaked out when rumors began circulating that the two were dating. Although they repeatedly denied being in a relationship, they dated for the first three seasons of the show.
It was later revealed that the two denied dating so much because they were afraid that the Gossip Girl higher-ups would be upset by their relationship. Rumors were confirmed and GG stars rejoiced once and for all when a paparazzi photo of the two was released. Although they broke up after about three years of dating, the two remained cordial and their characters continued to date on the show.