all 3.

CDG is definitely a dump, especially the death-star area that PMUA flies from.

LHR is also dumpy, especially CO's area

AMS is ok... not wild about it
....

FRA is no great shakes either, but at least the new sections are great.

MUC is awesome.

If you're not connecting in BRU, its really gross. there is a maze of areas you have to go through to get to the baggage claim, which is a dump. The check in area is dark and ugly. UA also doesn't pay to let its premium passengers use the premium security lines there.

UA Departs from "B", which I will say has nicer shopping and stuff than IAD C/D. The RCC has better wifi (BRU had 60 minute cards, no bathrooms and mediocre food, but better than the RCC).

And IAD has 10 guys, which is better than a single 5g. Wish I had a 5g burger instead of the 7-11 "grilled cheeseburger" on my flight.