Paine Field, KPAE is closest, about a 15 minute drive. It's where Boeing makes all the widebody jets. On of the runways is currently closed and is used as a parking lot for 787's! It has huge runways and rental cars.
Harvey Field, S43 is a small 3,000' runway that is privately owned but open to anyone that wants to operate there. It's about 20 mins away. No idea if it has rental cars.
Boeing Field (King County International) KBFI is about 30-40 mins away depending on traffic but is right next to downtown and has a great airplane museum on-field. Rental cars are available. It is under and around some crazy airspace, but the views of downtown as you fly past the buildings below the tops on approach are worth it.
