Credit: Giovanni Rufino/The CW © 2011 The CW Network, LLC. Photo: Blair and Dan in Season 4, Episode 17: "Empire of the Son"

Dan and Blair. Who’da thunk it? Well, lots of people: everyone who’s enjoyed their witty, hate-filled banter over the years, to be precise. Let’s revisit the highs — and, OK, a few lows — of their relationship.

Dan’s first UES brunch (Season 1, Episode 2, “The Wild Brunch”)
Dan’s first champagne brunch is also the first time he learns about Serena’s free-loving ways with Nate, the first time she keeps him waiting, and the first time he shoves someone into a tray of champagne flutes — all courtesy of one headbanded, slightly smirking “friend” of S’s. Dan, meet Blair Waldorf.

Dan comforts Blair after Eleanor’s fashion shoot (Season 1, Episode 4, “Bad News Blair”)
Lonely Boy realizes his Upper East Side nemesis has a heart. And all it takes is her mother and his girlfriend teaming up to utterly destroy Blair’s sense of self-worth.

Credit: The CW ©2008 The CW Network Photo: Dan and Blair Scheme in Season 1, Episode 18: "Much 'I Do' About Nothing

Blair and Dan take down Georgina (Season 1, Episode 18, “Much ‘I Do’ About Nothing”)
“I don’t normally do plots against people,” frets Dan as he and Blair press their ears to his phone so she can listen as he lies to Georgina.

“Don’t worry, virgin, I’ll talk you through it,” she sighs. Aww, you always remember the girl who took your scheming virginity, don’t you?

Dan tells Blair to go for it with Chuck (Season 2, Episode 8, “Pret-A-Poor J”)
“Wow. Someone loves Chuck Bass.” Dan blinks a lot to let Blair know how hard he’s holding back a tidal wave of Brooklyn-style judgeyness. But when a heartbroken B comes to him for advice about Chuck, he steers her on the right path. Whatta guy.

Blair outs Dan and Ms. Carr (Season 2, Episode 16, “You’ve Got Yale!”)
They can’t all be sweet memories. When Dan’s new girlfriend happens to be the teacher who’s been getting on Blair’s nerves, she has no qualms about mowing them both down. But Dan has the last laugh when Blair’s scheming lands her at NYU. With him.

Dan and Blair team up to keep Carter away from Serena (Season 3, Episode 1, “Reversals of Fortune”)
When Carter is sniffing around Serena, her two besties have no choice but to team up to keep him at bay with a fake restraining order. As usual, their loyalty to Serena brings out the best in both of them, allowing them to work together like one machine, fueled with a potent mixture of Brooklyn self-righteousness and UES trickery.

Dan gives Blair a social leg up at NYU (Season 3, Episode 2, “The Freshmen”)
Hell freezes over on Dan and Blair’s first day at NYU: Lonely Boy is the big man on campus, and the Queen B is a nobody. Luckily, Dan’s there to get her into Georgina’s party and offer her some sage advice. “No headbands in college,” he quips.  

Dan bucks Blair up post-Chuck (Season 3, Episode 18, “The Unblairable Lightness of Being”)
“Chuck and Blair, Blair and Chuck — who else could love me after what I’ve become?” Blair moans after the Chuck-Blair-Jack-hotel love quadrangle ends in tears. The only thing that could cheer her up? A few words from her favorite frenemy.

Credit: Giovanni Rufino/The CW ©2010 The CW Network Photo: Sneak Peek at Gossip Girl Season 4, Episode 11: "The Townie"

The Blair and Dan road trip (Season 4, Episode 12, “The Kids Are Not All Right”)
“What do you say we find that bitch and get us a little frontier justice?” We don’t even know what that means, but we love it. These two make a surprisingly good team as they once more present a united front between Serena and the world. Sadly, we’re betting the thing that keeps throwing them together will also ultimately be their undoing — they both love Serena far more than they care about each other.

The hand-hold! (Season 4, Episode 15, “It-Girl Happened One Night)
The brush of his hand on hers stood as the first indication that something deep and meaningful was growing between these two. But it got knocked from its OMG-est Dair moment pedestal in the blink of an eye.

The kiss! (Season 4, Episode 17, Empire of the Son)
It stopped time. 'Nuff said.