The following story contains light spoilers for Shang-Chi and the Legend of the Ten Rings.
There's been a lot of great action (and a lot of "meh" action) in the now 25 feature films and four Disney+ series of the Marvel Cinematic Universe. While 'Superhero' has, ostensibly, taken on its own form as a genre, it's also pretty reasonable to say that these movies and shows are 'action' movies and shows at their core. And when we watch, we're expecting to be excited, and enthralled at each and every moment. In Shang-Chi and the Legend of the Ten rings, we're reasonably entertained through the first part of the movie. But once Shang-Chi (Simu Liu) and Katy (Awkwafina) are approached by some thugs on a bus looking to take the pendant from Shang-Chi's neck, things kick into a different stratosphere.
The sequence—which appears to feature Liu doing much (if not all) of his own stunt work—is an instant marvel of action, fight choreography, and sound mixing/editing. We've seen lots of fights before, and while those can be exciting, the impact isn't really instantly felt. Thor: Ragnarok might be the best movie in the entire MCU, but when Thor is wiping out nameless bad guys in the opening scene with Mjolnir, we aren't exactly feeling that action as much as we're seeing cannon fodder at work.
In Shang-Chi's Bus Scene, the instant Shang-Chi reveals to Katy, the bad guys, everyone else on the bus, and, yes, us the viewers, we feel that action. When we see each punch, kick, and move up close, and hear the crunch and the impact, it's nearly impossible to even think about looking away. This scene continues with so much going on; the back of the bus rips away, and Shang-Chi hustles to save it while still taking on bad guys in a bus that's literally off the tracks moving downhill.
The only fight scene that really comes to mind instantly—at least on a hand-to-hand level; you can't really compare this sort of scene to the Endgame showdown with Thanos, or anything—is the Captain America: The Winter Soldier elevator scene. That scene, you may recall, is so beloved by fans and Marvel powers that be alike, that there's a tease in Endgame when you almost start to think that it could be happening again. (Steve Rogers in an elevator with a bunch of HYDRA agents will have that effect).
It's hard to say that one of these two legendary fight scenes is better than the other. Part of what makes the elevator scene so compelling is the fact that it's so serendipitous, so brutal. These are grown men fighting while moving in an extremely closed space, with the tension that comes before it really aiding just how great it is. Before the actual fight begins, Chris Evans gives one of the best line readings in the entire MCU: "Before we get started, does anyone want to get off?" There's really no topping that.
The bus scene doesn't have a similarly memorable one-liner from Liu or anything, but it does have a gorgeously choreographed sequence that goes on for quite a while. This is a sequence that took a lot of work, and that has every single thing in the right place at the right time. There's one moment where a spinning Shang-Chi is fighting guys before spinning around one of the poles on the bus and landing directly into the empty bus driver's seat, steering it back on course. I can't speak for anyone else, but at that exact moment in the theater, my action/superhero fan heart left my body and ascended; it did not return until after the movie ended.
The movie's credits scenes make it abundantly clear that Shang-Chi has a big future in the MCU. It's a good thing for that—because we could all watch fight scenes like this one (and, really, all of the hand-to-hand combat throughout the film) for a long time. And these sequences will only get cooler and gain a larger scale—assuming Marvel keeps the same energy—as Shang-Chi meets more of the universe's most popular heroes and villains.