Thanks for all your answers and insides. I have the global entry and therefore immigration time is not really a concern. The same with luggage as I hardly check-in any. The main points for me are connections to as much locations as possible (main on the east to middle part of the country) and delays.

Based on what I read EWR seems not an option. IAH might be a far west for my taste which leaves it to ORD and IAD. So far I had little problems into and out of ORD. I have little experience with IAD. Which of the two has more connections? The usuall arrival from Europe is around afternoon.