(ATTENTION: SPOILER - if you haven't seen it yet)
In the last episode of this sixth season, the identity of Gossip Girl is revealed - at last! Dan admits running the website and tells everyone that Jenny knew it all along.
On the other side, Bart Bass falls from the roof of a building and passes away (this time it's true ;). When the accident happened he was arguing with Chuck, who is considered by the police as a "person of interest" in the case. Consequently, with the help of his uncle Jack, Chuck finally proposes to Blair who accepts.
In the meantime, the businessman's death is a great relief for Nate Archibald, who runs The Spectator's newspaper and is no longer indebted.
The finale episode ends with a five-years flash forward in which Chuck and Blair already are parents, Dan and Serena are getting married, Nate has a successful career... and Jenny is Blair's partner in the fashion business! It also shows a new generation of the Upper East Side teenagers, including... A NEW GOSSIP GIRL !!!
The memorable end of an era :)