Success. The hard numbers aren't available for these two, but they probably make a decent salary from Gossip Girl. Still, their success isn't on par with some of the bigger names on our list, and why should it be? They're only in their early '20s. Blake has also appeared in the Sisterhood of the Traveling Pants series and the film Accepted, so she's paved the way for herself as a film and TV actress. Penn was in the teen comedy John Tucker Must Die, but most people just know him from Gossip Girl.
Attractiveness. On and offscreen, this couple glows. Blake's long legs and gorgeous hair have become Gossip Girl trademarks, and her style choices on the red carpet have been highly praised. while Penn's masculine features could only be described as "dreamy."
Popularity. People can't get enough of Gossip Girl, but these two don't have the name recognition yet that they need for booming popularity. Last month around 368,000 people searched Google for Blake and another 60,000 for Penn, placing them halfway down our list of most popular couples.
Staying Power. Even though they don't have a history of tabloid relationships, Lively and Badgley probably have a bright future of costar dating ahead of them. So far, they've only been together for a year, so don't get too attached -- let's just see what happens after they leave the show. Find out more about their PDA on and off-screen below.
Compatibility. Both Blake's Virgo and Penn's Scorpio tend to be overly critical, so these two run the risk of cutting each other down. Besides that, Scorpio has a tendency to be terribly jealous and insecure: Not ideal when your girlfriend is a total bombshell!