I live in ALX, so DCA is closer to me. If I’m flying to Europe, I prefer IAD, where I can get the 10pm flight to FRA, where I can connect on LH. If flying to the West Coast, I prefer IAD, if there’s a wide body operating, otherwise, I’ll fly out of DCA and connect at ORD or IAH.
I’m not a fan of EWR. I’ve misconnected there too many times to count.