Building your own PC is the best value choice usually, but it's not a great time to buy PC parts right now due to the shortages. There is no definitive "best" when it comes to PC though, as best is entirely dependent on what you are doing specifically with that PC. Someone that plays E-Sports title for instance doesn't need too powerful of a PC, but someone that wants to play Red Dead Redemption 2 as high settings will need a stronger PC. The same goes for non gaming stuff, so if you use video editing software or do 3D rendering in blender or something, then your PC will need to suit that task.
If you'd like to know a good company to buy a PC from, then I would suggest NZXT BLD as their PC's are not too badly priced and they make stuff with off the shelf parts. They have some questions they ask you on their site to help you decide how much you should spend. Hope that helps. I'm happy to answer more questions if you have any.