There are a lot of promising young heroes in My Hero Academia, but certain kids really rise to the top of the class. One of the top students in UA's hero circuit is Katsuki Bakugou. His overconfidence has gotten him into trouble in the past, but that isn't to say it's undeserved. He has an extremely versatile combat quirk in Explosion—he has the ability to sweat a nitroglycerin-like substance and detonate it at will.
No. 3 Hero Best Jeanist once observed that Bakugou has an excellent degree of control over his quirk. He might seem like a meathead at first glance, but he's highly intelligent and a masterful tactician. His classmates have to be at their best to go toe-to-toe with him. We'll see who can hold their ground and who's going down.
10 Can: Ojiro
Now, we don't want to disparage Ojiro. He's a cool guy. But he is mostly just a guy. His primary fighting style is martial arts and he's very accomplished at it, not to mention the very useful addition of a big, muscly extra limb. But Bakugou also thrives in close quarters combat and his punches are basically rocket-fueled. It'd be a little like pitting a very fit teenager against a pair of bazookas.
9 Can't: Kirishima
Kirishima's Hardening quirk and Bakugou's explosion seem well-matched. Explosion is an all-out offensive combat ability and Hardening lets Kirishima take a lot of strong hits without suffering consequences. However, Kirishima's quirk contributes to his offense as well as his defense, as taking a hit from his rock-hard fists is nothing to sniff at.
Kirishima almost had Bakugou beaten during the UA Sports Festival, until his quirk began to weaken. However, since then Kirishima has spent long hours being battered by Ojiro's tail to increase his stamina and durability, and he should be able to take Bakugou by now.
8 Can: Kaminari
Kaminari, on paper, should be able to take Bakugou in a fight. First of all, he has a degree of long-range combat ability since he's spent time honing his quirk. And then his quirk's primary ability is to paralyze anyone who touches him. Since Bakugou's primary mode of combat is close-quarters punching, this should be an easy way to give Kaminari an advantage. But Kaminari's biggest downfall is that he's an idiot and Bakugou very much isn't. If Kaminari tried to pull one over on Bakugou, it'd be countered before he finished having the thought.
7 Can't: Yaoyorozu
It'd be hard for most people to go up against Yaoyorozu when she's at her best. She has an almost god-like quirk allowing her to create any object she can understand from her body mass. This, coupled with her genius-level intellect, gives him an almost infinite about of strategies to counter her opponent's attacks. Bakugou is an accomplished tactician himself, but most of his strategies boil down to "rush in and punch." Yaoyorozu would be able to hold him off long enough for him to get frustrated and make a mistake, while she kept a cool head.
6 Can: Jiro
Jiro's quirk is both weirdly specific and oddly versatile. She has earphone jacks as part of her earlobes, which she can plug into pretty much anything and channel sound into them. The actual jacks are prehensile and whip-like, and she can also use them to eavesdrop. So apparently there's a lot of things you can get down when your ears look like the bottom half of some headphones. Unfortunately for her sound-based abilities, Bakugou's quirk is Explosion, and explosions are very loud, rendering her almost useless against him.
5 Can't: Todoroki
Todoroki's combat is almost the polar (heh heh) opposite of Bakugou's. His attacks are primarily ranged, as both his ice and fire quirk have a large radius of effect. Also, where Bakugou rushes in and attacks on instinct, Todoroki has spent years honing his quirk under the tutelage of his domineering father and is a master strategist.
Even during their bout in the Sports Festival, where Bakugou was declared the winner, he admitted that if Todoroki had used his full power he would have won. Now that Todoroki isn't afraid to use his fire, he'd definitely come out on top.
4 Can: Tokoyami
Tokoyami has one of the strongest quirks of all of Bakugou's classmates. Dark Shadow, a sentient shadow creature bonded to him, can be used for attack, defense, and mobility. He handily defeated Yaoyorozu during the Sports Festival and even managed to hold off Bakugou for a time. However, one of his biggest disadvantages is Dark Shadow's weakness to light, and Bakugou's explosion produce bright light—every one of his attacks also serves to weaken Tokoyami. In addition, Tokoyami doesn't have nearly the degree of control Bakugou has over his quirk, making it unpredictable and open to counterattack.
3 Can't: Midoriya
Midoriya is Bakugou's long time rival and the two of them have probably fought more than any other pair of characters. Both boys have won against the other on multiple occasions, so it's hard to definitively say that Bakugou couldn't beat him.
However, considering that Izuku has held his own and even beaten Bakugou using a fraction of the power of One For All, it stands to reason that as he continues to gain control over the immense power, Bakugou won't be able to stand against him for much longer. This doesn't even take into account Midoriya's tactical mind, constantly observing another hero's moveset, and his frankly idiotic amount of determination.
2 Can: Uraraka
Uraraka's quirk seems poorly suited for a battle against Bakugou, since it has highly limited offensive capabilities and relies on coming into close quarters. However, despite these limitations, she's proven herself a formidable opponent. During the Sports Festival, she was able to catch Bakugou off guard more than once and even forced him to use his full power to defeat her. She has excellent control of her quirk and its different applications. Unfortunately, Bakugou is perhaps the one student who would still be able to beat her after being levitated; he can propel himself through the air with his explosions.
1 Can't: Shinso
Shinso has finally been admitted into the Hero Course, though not in Class 1-A. He deserves it, as his quirk is hugely powerful and Shinso is committed to using it for good. On the surface, there aren't a lot of combat applications for his ability. However, they're excellent for subduing a single dangerous opponent. All he has to do is get his target to respond to him verbally and he's able to control their body. And we all know Bakugou couldn't keep his big mouth shut to save his life. It's almost too easy.