If your budget is below £200, then the Intel 12th gen 12400F CPUs should be suitable. For a budget of around £300 who want to invest long-term then it would be wise to purchase AMD Ryzen 7600 CPUs. For the above budget segment one can suggest; Ryzen 7 7700, Ryzen 9 7900, and Ryzen 7 7800X3D, the latter is considered the best for pure gaming. However, do ensure that you match the CPU with the right kind of GPU, consider how many more cores you may require for the tasks other than gaming.