I'm a bit surprised IAD and BWI hasn't gotten more flack.

IAD - well, it's pretty obvious why IAD is terrible. Middle of nowhere, public transportation basically consists of two options:

- Private bus to peripheral train station (West Falls Church)
- Bus to less peripheral train station (i.e. Rosslyn) or kind of business area (still, however, far from where anyone actually lives in DC - L'enfant).

BWI - while BWI does have a rail link (well, a shuttle that goes to the train station), it can be severely limited for weekend travelers, as it's limited to hourly regional service (and if memory serves, the Acela hop from BWI to Union Station is still absurdly priced).

On a positive note, a small US city that actually has it right is Pittsburgh. The PIT airport bus should really be renamed the university airport bus (it terminates in front of CMU and mostly services U Pitt and CMU students, which is especially apparent if you're traveling around Thanksgiving, the holidays, or spring break), but it appears to serve downtown and Oakland office workers fairly well.

HKG still has everyone beat, in my opinion. I don't think any other service allows you to check in luggage from downtown (besides some of the Japanese convenience store baggage check services).