A very popular and impossible question to answer. If you’re not interested in building the PC yourself, you should of course buy a pre-built one.
However, what you really need to consider is how much power you need, and here, we will always recommend you future-proof the PC a bit. Ensure the components in the PC are more powerful than what you actually need. That way, you won’t have to upgrade it when the next AAA game hits or when your 3D-rendering program gets a massive upgrade.