Three park & ride lots will have shuttle service to Seahawks games. These are also cash only, $4 each way, and happen to come from lots where routes 41, 255, and 554 are just as convenient, and cheaper.
For out-of-town visitors, Link is your express from the airport to Century Link Field, and the first leg of your connection to Husky Stadium (until UW Station opens in 2016). From downtown, routes 255 and 545 get you to Montlake Freeway Bus Station, from which you have a picturesque half-mile walk north to Husky Stadium across the Montlake Bridge.
If going to Century Link Field, an all-day ticket on Link is your cheapest option ($5.50). Choose Airport Station to Westlake Station, so you have all-day access to the full line.
If you are going to Husky Stadium, I would suggest getting an ORCA card at Airport Station ($5 – Yes, we know it is by far the most expensive bus smart card in the country.). ORCA allows for free transfers within two hours. Load it up with at least $5.50 in e-purse to get to and from Husky Stadium. The regional day pass option is also available for a limited time, at $9, plus the cost of the ORCA card. Sound Transit has a snazzy video to help you out.
Don’t even try driving to the game. You will be stuck in gridlock, and you will not find parking.