Any admob replacement for banners?

Is there any replacement for admob banners? It may have less fill rate, that is fine, but at least should be a trusted company.

So far, we have mobilecore, appnext - they don’t have banners, startapp (banners are not good). Airpush (EULA).
In general, any new trusted ad company?

startApp is the one you can think about, i had been using it for over 1 year