I agree with @antix
@hgy29 I agree with @Ninjadoodle and @antix, but I would also go as far as to prioritise the ads further into most commonly used (admob being the first). We also use Applovin for reward ads, but I wouldn't know which one should be second etc.
For me, ad platforms AppLovin then Chartboost perform the most. Admob was very disappointing.