I started with Fedora. Installed, seemed nice. Then I did a dnf update or something like that. It froze for 4 hours in the middle of the install. So I hit ctrl+z. When I restarted my computer GRUB was attempting to boot an OS version that did not exist and I had to manually try to figure out how to fix this which I was in no mood to do after having the OS for 10 minutes. Also apparently the newest version of Fedora didn't have the concept of turning off auto lock? Or a timer. I'm not sure, but the end result was that if I tried to watch a movie for more than 10 minutes my desktop would helpfully lock, continuing to play the movie.
So I then installed Ubuntu, which was fairly straightforward. Then deleted the couple of things that felt like advertisements (like a direct link to Amazon on the quickbar or whatever it is). Overall, was a pretty good experience until I installed the proprietary Nvidia drivers. Then for some reasons movies (DRM-free files) would stutter. At that point I was thinking about doing some C# development in visual studio anyway so I looked into dual boot installing windows 10 while having Ubuntu installed, and while there are a million articles on how to install Ubuntu with Windows 10 already installed, the reverse did not seem to be true. So I just wiped my system drive and reinstalled Windows 10, which helpfully activated based on my hardware profile even though I'd neglected to save the key.
Also, depending on what kind of C# development you do, VS Code can be very nice. DotNET Core is very straightforward to work with, and targeting the full frameworks with Mono is doable with a little bit of tweaking. If it's Unity, then the debugger plugin will be completely useless on Linux, and you'll have to use the very latest beta version of the editor.
In general if you stay away from anything too esoteric, and avoid hardware that needs proprietary drivers (e.g. nvidia graphics, broadcom wifi etc...) most things should work out of the box, but it's a good idea to do a bit of research on anything you're thinking of buying if linux compatibility is desired.
There are also various smaller vendors like system76 that sell laptops with linux pre-installed.
Here is a list of certified vendors for Ubuntu:
I had HP and Compaq laptops that ran Linux as well.