2. Blake Lively and Penn Badgely
The actors, who played Serena van der Woodsen and Dan Humphreys on the show, first met on the set.
Their characters got together early in the first season, which ensured they spent plenty of time getting hot and heavy while filming.
Reports started to circulate in late 2007 that the actors were more than just costars, but Lively and Badgely denied their involvement until they were photographed kissing in Mexico in early 2008.
Once the cat was out of the bag, the pair opened up about their relationship and became one of NYC’s hottest celebrity items for the next couple years. Both actors saw their careers begin to thrive as Badgely starred in the hit comedy “Easy A” and Lively showed off her acting chops in the thriller “The Town.”
In September 2010, the news broke that the couple had broken up. The actors were obligated to continue working together (and reports from the set revealed that they both remained very professional), but they never tried to rekindle their off-screen love.
“Gossip Girl” ended in 2012, and Dan and Serena actually got married in the series finale, but by that time, Badgely had moved on to dating Zoe Kravitz and Lively was engaged to actor Ryan Reynolds. The CW stars are no longer friendly since their show ended.