With the contractors, we have:
* The Space Shuttle - a death trap and reusable in no practical sense. Refurbishment involved near rebuild of large components. Often used as proof about how reusable rockets were not financially viable prior to F9's reliability.
* SLS (ie the rocket to nowhere) - too expensive and too slow to build to be worth using unless literally mandated by law. Is too rough of a ride, Orion's screens had to be modified to flicker in sync with the vibrations so that they would be readable. Congress (in blatant bias towards Boeing) attempted to mandate Europa Clipper to launch on it instead of Falcon Heavy, only backing down when told that they'd have to give Clipper an extra $1B (in addition to the $3B for an SLS launch) to make it able to handle the conditions imposed by SLS. Continues to be a burden on NASA's budget by eating up funding for other projects.
* Vulcan being forcibly neutered down to the bare minimum functionality needed to sell national security launches, because the original proposal would've reduced costs and removed the one existing need for SLS. They were proposing an upgraded second stage which would be able to be refueled in orbit and would've been able to carry Orion. Boeing tried to get the designer of that component fired. Also has the bare minimum to be 'reusable' by having an eventual goal of detaching the first stage engines from the body and splashing them down via inflatable heat shield. Basically does just enough to be a minimum viable competitor to F9 in national security launches and nothing more.
* Starliner with its initially poor software, stuck valves, fire resistance system that actually catches fire and parachute issues. Here Boeing got NASA to pay them extra money on top of the agreed upon fixed-price contract, holding domestic access to the ISS over them. Also tried to get SpaceX's contract cancelled and that money also awarded to themselves for no additional changes. The vehicle is designed for the bare minimum required for the contract (only 2 being built), with no interest in separate commercial activity the way Dragon is used in.
* JWST (ie the telescope that ate astronomy) - massive delays, budget overruns and serious failures in testing which caused another ~5 year delay. It was nicknamed "the telescope that ate astronomy" due to the budget overruns, which harmed several other telescope projects.
* Hubble - the work done directly by NASA was mostly fine, but contractors had large cost and schedule overruns, with the mirror issue due to a failing contractor and Lockmart facing cost overruns + not taking the initiative with designing the spacecraft for the telescope.
There is a heavy Boeing bias here since the main culprit in half of these examples is Boeing. But at the moment these were the main cases that came to mind.
The sad thing about these cases is that the early excuse for not taking risks with new companies like SpaceX was that they didn't have spaceflight "heritage" and couldn't be trusted to not cut corners in important places, with the implication that the established companies would be charging less if they could without compromising safety/quality.