Perhaps only because it is a little bit small but the layout is relatively easy to understand, navigate, and traverse in a short amount of time whether arriving, departing, or making a connection. If your transfer gives you the choice between walking from one wing to the other and using tram: use the tram (it connects both ends and avoids the high traffic areas at the center of the airport). Security and customs are the most professional, polite, and straightforward I have encountered (complaints about retarded TSA policies aside as those aren't the fault of SEA). Staff and facility and clean and friendly. Food selection surprisingly good/affordable.

World class airport. Easy access from the drop-off area, or from the parking garage. Be sure to write down your parking space number, because the huge garage looks the same from every point. Excellent choices for food and beverages, and the security areas are very straight-forward and organized. There's not a whole lot of walking required to get from the check-in to your departure gates, and from the gates to the baggage claim. The trolley does the work for you.

I have visited many airports in my recent years of travel, but no airport I have been inside before reaches the standards of SEA. The numerous signs and staff available make certain you have no trouble of finding what you need (especially your terminal and gate). The transportation between terminals is quick and convenient. The airport is well kept, the food variety is great, and the view is amazing when it comes to watching airplanes land and take off.
All in all, I would love to come back to Seattle, if only to go to SEA again!!!!

This is a nice facility especially if you like to watch aircraft take-off and land. The place is very clean. The staff are friendly and very helpful.

The public transportation is great with buses and taxis always available. Soon there will be a light rail system that runs from downtown to the airport.