My favourite tool is GPU Screen Recorder - https://git.dec05eba.com/gpu-screen-recorder/about/
This is a screen recorder that has minimal impact on system performance by recording your monitor using the GPU only, similar to shadowplay on windows. This is the fastest screen recording tool for Linux.
It works with AMD, Intel and Nvidia GPUs. It is also the one that performs better. Official repos AUR or Flatpak, or you can install from the source above. The flatpak already comes with the UI gtk https://git.dec05eba.com/gpu-screen-recorder-gtk/
Other tools I used were OBS and Steam - you can enable Steam to record your games in the Settings > Game Recording > Record in Background
OBS was very laggy for me.