The selection at the 1st Ave store is amazing, ranging from specialty invitiations (custom made or DIY) to scrap book supplies, to boxes and gift wrapping supplies. The prices are quite reasonable - in fact they are substantially cheaper than many online stores. The staff is helpful yet allow you to wander the aisles of the warehouse style store in peace. The store is particularly helpful to those planning large events or weddings as it is really one stop shopping for all your projects. There is also a second location in Bellevue but I highly recommend making the trip to Seattle as the selection and prices are much better.
There is also tons of free parking.