Hi Buenafe,
I think AVE is the fastest and the most confortable way. Prices are not so bad from 8.500 pesestas you can get to Sevilla in about two hours and a half.
If you`re not too tired and don`t have a lot of luggage the Metro is the cheapest way to arrive to Atocha station but it will take you a long time. As Afuegolento says check out Aerocity rates you will be surprise.
Have a nice trip!!
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Celia
Airport shuttle, limousine service and car rental.
http://www.aerocity.com [This message has been edited by Celia U (edited 10-18-2000).]