By The Goblet of Fire, Draco Malfoy is firmly established as Harry's nemesis (in school, anyway), and busy causing all kinds of mischief. Despite not being able to have any impact on the Triwizard Tournament itself, Draco manages to make anti-Potter magical badges (which the Hufflepuffs wear too), to attempt to curse Harry when his back is turned, and even to mock him for the trauma that he goes through in the final task.
Despite this range of particularly heinous choices, though, Draco does manage a few surprisingly good moves throughout their fourth year at Hogwarts. Whether self-serving, or accidentally beneficial (despite the worst intentions) these are the choices he made that showed some level of maturity, intelligence, or a positive outcome.
Warning The Trio To Keep Hermione Safe
At the Quidditch World Cup, Draco is quick to sneer at the Trio, and warn them to keep Hermione out of sight - as a Muggle-born, she could well be a target for the wizards rioting and tormenting the Muggle camp-owner. This seems, at the time, like a simple sneer at Hermione and her background, even a threat, but it was actually a solid choice - and a surprisingly positive one.
As fans know, later in the series, Draco proves that for all his bluster, he doesn't actually want to really harm people. He refuses to give Harry up when he's at Malfoy Manor, but before that, he's clearly tormented by his status as a Death Eater and his task of killing Dumbledore. Well before then, though, he's warning the Trio to keep Hermione safe - and while it seems like an insult, it's actually excellent advice. When they weren't entirely sure what was going on (and Draco definitely was), he may actually have been seeking, on some level, to protect her.
Not Immediately Giving Up His Father
Had Draco not been such an obvious Slytherin, he might have made a solid Hufflepuff - as he is loyalty to his family to a fault. He even manages, by this point in the series, to put his need to protect his family above his desire to boast to his schoolmates about how important he is. When the Quidditch World Cup devolves into chaos, Harry shoots a comment at Draco about Lucius being one of the masked figures - and although Draco absolutely knows this is true, he actually manages to swallow his need to brag about his family's power and protect his father's identity.
This may be a decision that was borne more of fear than of loyalty, and it certainly isn't an admirable choice to be on the side of the Death Eaters in this situation, but this was clearly the best choice for Draco. While a younger Draco may have been tempted to boast about his father's actions, this Draco knows that protecting his father matters more - even if just to save his own skin!
Taunting Harry
Draco taunting Harry is nothing new (although his Potter Stinks badgers are a new level!), but in this case, his bullying may have worked in Harry's favor! For one thing, Draco's taunts (and attempt to curse Harry) ended up creating a bond between him and Moody - and while this wasn't ideal (as Moody was Barty), it did actually lead to him getting some very useful pointers that kept him alive through the tasks.
For another, Draco's taunts may have been a big part of pushing Harry to actually take Cedric's advice about the egg, and take it in the bath. If he hadn't figured out the clue (at the last moment, admittedly), he wouldn't have been able to even complete the second task.
Going To Rita Skeeter
In the short term, this is a terrible choice of Draco's. He went to Rita in order to spread malicious rumors about Harry, and to cause problems for him - and it worked. However, it worked so well that it got to Hermione - and that's rarely a good thing for anyone working against her! Draco's lack of secrecy also allowed Hermione to figure out Rita's secret, and blackmail the unregistered animagus into giving up her acid quill.
This not only ended up working out for the best as it prevents Rita from writing any more vicious lies, but because it put Rita in Hermione's back pocket. When no one was listening to Harry the following year, this allowed Hermione to get Harry an interview - something that made a difference, and that she wouldn't have been able to do without a hold on Rita... courtesy of Draco.
Taking Pansy To The Yule Ball
One of Draco's few decisions that was actually good for him, not because it accidentally worked out well for the Golden Trio, was taking Pansy Parkinson to the Yule Ball. While the two didn't eventually end up together (a refreshing change from many of the Harry Potter characters, who all seemed to marry their school sweethearts), it was likely good for Draco to have some semblance of a normal teen experience - one not centered on Harry Potter!
Given that Draco was otherwise essentially only seen with Crabbe and Goyle, who were meathead backup more than friends, it was probably also a good thing for Draco to have at least one relationship in his life with something approximating real respect and care for one another. At least, fans can hope!