If they serve your needs, they are a good choice. OECD test guidelines, including those on genotoxicity, are the test methods of choice for regulatory purposes around the world.
In principle, as mentioned by Sebastian, the OECD guideline test methods are the gold standard and are generally accepted worldwide. However, you should remember that they are guidelines not protocols, so you will need additional sources if you want to perform such studies, in fact, it is best to get some training at an experienced lab before you start. Furthermore, it also depends on the purpose of your studies, are they for regulatory, investigative, or screening purposes? Depending on your purpose you may find a non-OECD method that is more suitable.