The actress - who has starred as Serena van der Woodsen on the CW drama since 2007 - told Bullett that she "plays a caricature of [herself] on the show".
"I don't think I'd say, 'Watch Gossip Girl for my best quality of work'," she admitted. "But I am very lucky to have had that experience."
Lively added that she is looking forward to "the next challenge in life" once Gossip Girl ends in 2013.
"It'll be bittersweet when it's over," she said. "I think the best way to describe it is like someone who really enjoyed high school, and [now] I'm a senior and I can't wait for the next thing!
"Gossip Girl was so great, but what's the next challenge in life? Because, you know, six years is a long time."
Gossip Girl airs on The CW in the US and on ITV2 in the UK. The series will return for a final ten-part season in late 2012.
> Gossip Girl: Season finale 'The Return of the Ring' recap
Watch a clip from the Gossip Girl fifth season finale below: