Lorelai and Rory might be the most important relationship in Gilmore Girls, but Lorelai and Luke are a close second. This slow-burn love story takes a full seven seasons to come to fruition, with plenty of sexual chemistry, near-misses, romantic dreams, and even a few dates, breakups, and makeups in between.
Essentially any episode of Gilmore Girls is a perfect one for Lorelai and Luke fans, from the pilot, where Lorelai's opening line is to say 'please Luke', to the finale, where they finally kiss it out at Rory's goodbye party. However, for those die-hard Lorelai/Luke fans, these are the episodes that made the biggest difference, and that made fans go all warm and fuzzy over the relationship.
That Damn Donna Reed (S1, Ep 14)
This episode is more commonly remembered for being the one where a cat-sitting Rory decides to go all 50s housewife on Dean, but Luke and Lorelai get their own moment here, too. For one thing, Lorelai gets grilled by her mother on their relationship, and hints that maybe there's a little something more than just coffee-supply and friendship going on. For another, Lorelai ends up very close to Luke when the two are trying to re-paint the diner... making this an episode that told fans all they needed to know about where this was going.
Love, Daisies, and Troubadours (S1, Ep 21)
This may not seem like the most romantic episode for Luke and Lorelai, because it sees Lorelai and Max getting truly serious, while Luke seems to be moving on with his girlfriend (and also ex-girlfriend) Rachel. However, this is an episode that proves that even if they didn't end up together romantically, they would always be there for each other, no matter what. Luke tells Max that he will 'always be around', and that's more touching than pure romance.
Lazy-Hazy Crazy Days (S3, Ep1)
In many ways, this isn't one of the really big Luke/Lorelai episodes, but it's a big one because it's their first kiss... in Lorelai's dream, of course. The episode begins with a dream where Lorelai and Luke are married, living together, and Lorelai is pregnant.
This, of course, freaks Lorelai out, and as she is avoiding Luke (after her explosion when Rory is injured in a car accident with Jess), he doesn't appear again until the very end of the episode. Then, in need of coffee, she heads into the diner, and they make a move toward reconciliation. It's an episode that hints at the future, and takes them a step closer to it at the same time.
In The Clamor and the Clangor (S4, Ep11)
Luke and Lorelai have another fight in this episode, when Lorelai hears that he has moved in with his girlfriend - and it's not the moving that bothers her (ostensibly), it's the fact that he didn't tell her about it. Of course, this also sees the two of them make up, thanks to the common enemy of the church bells. The best part of this episode is that Lorelai really shows how much having Luke nearby means to her (and, by extension, how much he means to her), while he shows how important Stars Hollow is to him by not actually moving... just claiming he did to placate his partner.
Luke Can See Her Face (S4, Ep20)
After four seasons of these two pretending that they are really, truly, just friends, this is the episode where it really hits Luke - he is in love with Lorelai. And, hilariously enough, the thing that makes him realize it are self-help tapes. He's listening to them in a surprising attempt to grow as a person, and something that is said makes him realize that it's Lorelai that always makes him feel good. It's her he always wants around. It's her that he thinks about, all the time. It's adorable.
Last Week Fights, This Week Tights (S4, Ep21)
This is a fan-favorite episode because it involves TJ and Liz's wedding, and everyone wants to see some renaissance goodness, but it's a perfect one for Luke and Lorelai fans because it's their first proper date.
After his self-help-inspired realizations that he wants to be with Lorelai, Luke asks her to the wedding, and they have some beautifully romantic scenes... followed by the suggestion of an actual, real, date.
Written In The Stars (S5, Ep 3)
On an official date, Luke goes above and beyond to let Lorelai in, and it's amazing. For one thing, it's incredible to see something beyond Lorelai's world in Stars Hollow, and to see that Luke does actually have some form of life outside of her, Jess, and the diner. As he takes her to a favorite restaurant, they get to navigate some first date weirdness, but it all works out in the end when he whips out the horoscope from when they first met, and tells her that he is 'all in'. Of course, this is their first date, and the first time they sleep together, which makes it an amazing episode for the couple, but it's also the episode where Lorelai accidentally clues the whole town in and they end up being discussed at the town meeting.
So... Good Talk (S5, Ep 16)
A few episodes prior, Luke and Lorelai take a break, and this is the episode where they (thankfully) get back together. Possibly the best thing about this reunion is that it's not driven by Luke, Lorelai, or even Rory. It's Emily, who finally sees how important Luke is to Lorelai, and who goes to the diner to step up and tell him that she will stop meddling in their relationship. And of course, there's that reconciliation kiss.
A House Is Not A Home (S5, Ep22)
Another huge moment for Luke and Lorelai, as there's a proposal in the offing - but it's Lorelai who proposes to Luke. In many ways, this isn't as sweet as it should be, because she's doing it after a huge fight with Rory, when she has stolen a boat and decided to drop out of Yale. In some ways, this could be seen as reactive, but to most fans, it's seen as the moment that she realizes that Luke will always be in her corner.
Lorelai? Lorelai? (S7, Ep 20)
It would be easier to include the finale of Gilmore Girls, as this is the moment that Luke and Lorelai reunite, yet again. However, attention must be paid to this episode, where Lorelai and Luke are on the road to reconciliation... and she serenades him at karaoke with 'I Will Always Love You'. It may have started as a song for Rory, but it doesn't take long for this to become the moment that the whole town knows that Lorelai and Luke are going to be back together again soon.