They're so cool and some are just downright beautiful, especially the colors and shock diamonds produced
The RS-25 is one of the most beautiful rocket engines ever made and one of my favorites. The brief overexpanded gas pressure visualisation at the engine rim on startup and the beautiful blue shock diamonds surrounded by almost clear exhaust makes it to look almost magical. It also has a beautiful purr and makes any Space Shuttle of SLS launch a treat to behold
Similarly the Space Shuttle and her sister ship the Buran are some of the prettiest ships ever flown, the space shuttle straining against the huge steel structure (1:29) holding it in place immediately before launch is beautiful. Sadly the Buran is little documented and flew only once. As opposed to the American Space Shuttle which had 5 flight worthy ships and one testbed, the Buran Program had only one flight worthy ship "Buran" ever built with the second ship "Ptichka" was never fully finished still sitting at 95% complete in a decaying warehouse. Despite their similarities there are important differences including the very advanced robotic landing computers abord the Buran, and the fact it did not contain the engines for launch like the space shuttle did, instead it was strapped to the side of the Energia heavy lift rocket. This meant that engines had to be remade for each launch but also meant the Energia could launch other payloads of similar mass to the entire Buran, not just to the shuttle's cargo bay. Sadly the Energia would only complete two launches before the Soviet Union's collapse led to the project's cancellation. Sadly Buran was heavily damaged in a roof collapse in 2002 and Ptichka sits still unfinished in a near abandoned warehouse
The Concorde isn't a rocket, sadly, but it is very cool and can go very fast so I'm including it in my list, when you hear Concorde you just think, faster than sound, but it actually went over twice the speed of sound, it wasn't just a bit faster than commercial aicraft it was over twice as fast. The Concorde had a max speed of Mach 2.04, which makes it faster than many high preformance military jets, its faster than the F-35 (Mach 1.6), Rockwell B-1 Lancer (Mach 1.25), Sukhoi Su-57 (Mach 2.0), Shenyang J-35 (Mach 1.8), and the Chengdu J-20 (Mach 2.0). The fact it was commercial and not military makes it even more amazing. The Concorde also had a Soviet sister ship the Tupolev Tu-144. Back