The Daltons sometimes became even more popular than Luke. In fact, in the XilamAnimation produced series The Daltons, Lucky Luke doesn't even appear, and the focus is on the Daltons as they try to escape from prison.
Rantaplan, to the point he got his own series.
A minor example with Calamity Jane.
Germans Love David Hasselhoff: Like many French-Belgian comics, Lucky Luke is extremely popular in Scandinavia, especially Sweden, to the point that there's a long-standing live show at the western-themed amusement park High Chaparral, featuring Lucky Luke and the Daltons.
The dream sequences from The Bride of Lucky Luke, Luke is having Counting Sheep dreams after being roped into helping a wagon train of single woman across half the frontier to a town of single men. The sheeps heads suddenly turn into the women's heads, leading to a Catapult Nightmare for poor Luke. It's repeated later in the story when he's forced to stay in the town to chaperone one of the women, an Irish girl named Jenny, who's fiancee got himself jailed for several months after trashing the saloon in celebration of his marriage. This time it's just Jenny's face, but equally unsettling.
One bizarre short story revolves around Luke looking for a man who has apparently stolen Jolly Jumper, with the theft having taken place over a year ago. His only clue is a pants button the thief left behind, but after finding a man wearing said pants it turns out they were part of a Chain of Deals, and when Luke finally tracks down the man who sold them, it turns out he got them from the body of a man who was hanged for selling horsemeat, making him faint dead out of shock. Thankfully, it was All Just a Dream
The Daltons coming within seconds of getting hanged when their sentences are changed to execution. It's especially disturbing how the whole town treats it like a public event, complete with little kids asking to be held up so they can watch (which is completely historically accurate by the way).
Technically, Laurent Gerra is the latest of the numerous Goscinny's successors, while Achdé is pretty faithful to Morris' drawing style.
Replacement Scrappy: A rare inversion; the second set of Daltons have ended up becoming much more famous and iconic than the original.
Seasonal Rot: When Morris died and the series was written by comedian Laurent Gerra. It's not unreadably bad, but it's very noticeable that it's no longer made by Morris. The thinly-veiled celebrity and politician parodies don't help.
Ship Tease: With actress Sarah Bernhardt if you can believe it. After working as a bodyguard for her on her first tour of the U.S, she gives him a personal autographed photo with the following message written on it: To Lucky Luke, who's only lonesome because he chooses to be.
Tear Jerker: In A Cure For The Daltons, the psychatrist's treatment actually works on Averell, who begins to regret his life of crime and his underlying good nature shines through. At one point, he actually breaks down sobbing after he steals thread from a store (the psychiatrist had gotten him interested in needlepoint).
In the opening, Senator Beuregard is violently opposed to the idea of rehabilitating criminals, and it's all but stated he's like that because of his abusive father.
Villain Decay: The Dalton Brothers have suffered quite a bit of it over the years. In Les Cousins Dalton, their 1958 debut, they get the best of Lucky Luke, forcing him to service for a time. Within the story each brother is given different character traits. Joe is the mastermind, William is obsessed with guns and using everything on sight for target practice, Jack is a master of disguise. Averell is naive but also a superb boxer. In fact he fights Luke to a standstill. Luke only wins by using his cunning, not his fists. The two combatants agree to meet for a rematch and retreat to their own rooms for sleep. Only Luke manages to releases mosquitos in Averell's room. The following day, Luke is fresh after a good night's sleep, Averell has not managed to sleep at all. He can barely walk, much less fight. Since then, several stories portray them as incompetents, and in some stories William and Jack may as well be interchangeable for all the characterization they get, if they are not relegated to background status within the group, where Joe and Averell tend to get the spotlight almost exclusively.
"Weird Al" Effect: At least in Francophone Europe and in Québec, the Dalton brothers from Lucky Luke are much more recognizable than the historical Dalton gang.
"I'm a Poor Lonesome Cow-boy" in its full glory which served as the ending theme for Daisy Town (and later truncated for the 80s animated series co-produced by Hanna-Barbera) has become a classic tune for the title character and its franchise.
Big-Lipped Alligator Moment: In Go West: A Lucky Luke Adventure, there is a woman who sings a musical number that has no relevance to the plot.
Nightmare Fuel: In the movie Daisy Town the showdown between Luke and the Daltons starts of as rather sinister with ominous music playing, the Daltons ready to kill and the whole town pausing at whatever they were doing to listen to the sound of the approaching combatants. And then the whole thing ventures to purely comedic Nightmare Retardant thanks to Lucky Luke's plan.
Foe Yay: Lucky Luke and Joe. Constantly. Not only is Joe obsessed with killing Lucky Luke, but he often postpones his original plans just to try to kill him. The title of the episode "Cuff Love" is also somewhat suggestive (seeing as it is focusing on Luke and Joe)
Heartwarming Moments: In the episode "Dalton Junior" the Daltons start taking care of a baby given to them. Joe is very reluctant towards the idea of keeping the baby, but over the course of the episode he warms up to him and even goes to the doctor because he feels genuine love and cannot comprehend it. At the end of the episode the baby and Joe are separated but it's obvious that Joe can't forget him.
Tear Jerker: Despite the original source material and any other adaptations thereof is far from being a treasure trove of emotions (given that it's a comedy, spaghetti western parody and all), there's something surprisingly poignant about Cynthia's plight in the "The Dalton Cowboys" that makes you sympathize with her a bit as the episode goes on. Sam laments that being in her thirties, she's not getting any younger but he still hopes that she will find a husband. Upon meeting the Daltons, she immediately develops a crush on Averell and becomes an Abhorrent Admirer who makes Averell so miserable, he begs for her to let him go back to be with his brothers. After thinking she's been deceived (thanks to Joe's plan when he was disguised as Averell and having tricked her into opening her father's safe), she seeks vengeance on Averell during her rampage but Lucky Luke stops her just in time, and tells her that love has made a crazed fiend out of her to which she responds with tears. Her father says that it's her first love and acknowledges that it's always the worst. He reassures Luke that she'll get over it. Then we cut to the ending — once Luke takes the Daltons back to prison, Cynthia steals one last glance. She gives way to a whimper (possibly repenting), then goes back to fixing the farm's roof, more upset than ever. It's one of the few, if not only, truly bittersweet endings.
Judging from the situation Averell is put through, he's a total woobie from start to finish with Cynthia's relentless crush and Joe forcing him to stay on her good side for the sake of revealing the location of her father's money in order for them to steal it. His smile as Luke sends them away back to jail is the "sweet" part on the aforementioned bittersweet conclusion of the episode.
A minor one, both on account of lasting very little and being predictably an act, happens in the "Vultures in The Plain" episode. Our cowboy befriends and speaks kindly to one of the similar-faced undertakers named Barnaby who is peer-pressured by a much more sociopathic undertaker named Deadflower to raise his clientele by naturally raising the body-count. Luke decides that the best way to deal with Deadflower is to fake his death in a duel, which leads to Barnaby breaking down and crying over losing the only person who ever spoke to him as a friend. Even though he didn't really die, the genuine pain in the words of a man who got used to being avoided all his life, can be heartbreaking.
Most prominently, the Game Over screen, where you first see someone pointing a Gun at Lucky Luke's back (a Continue Screen available only in Sheriff mode) and then shifts to Barnaby the same-as-always undertaker as he holds his hands in cynical delight, with a poster reading Game Over (in typical "western" font). Can easily become High Octane for the most sensitive.