I don't think BWI is too bad. It's crowded, but certainly not that bad. I don't mind that airport to be honest, aside from the rental cars being located halfway to West Virginia.
If you want an absolutely awful WN airport, go to SAN when there are delays or when a cruise ship docks. It's about as bad as it gets with the hour long security line (thank god for the A list line being enforced now!), the one bathroom behind security, the lack of room with people sitting on the floor everywhere and so on. DAL is pretty bad as well (but they're "fixing" it).
LAX is another bad one, but that airport in general is just a disgusting mess that is a disgrace to the City of Los Angeles.