Youtube.com : $1.650.000.000 : Google bought Youtube and all services for the most expensive price on the web.
Sex.com : $14.000.000 the most expensive domain sale of all the time( the word "sex" is the most searched word online)
Fund.com : $10.000.000 sold in 2008
Porn.com : $10.000.000 in 2007.
Business.com : $8.000.000 in 1999 by an californian advertisement program.
Diamonds.com : $7.500.000
Beer.com : $7.000.000 (why not drinks.com , water.com, alcohol.com etc ?)
AsSeenOnTV.com : $5.100.000 in 2000 and probably the most terrible expensive domain name
Korea.com : $5.000.000 good choice for tourism/travel and export/import business (what would be the price of travel.com or holiday.com ?)
Casino.com : $5.500.000 ( why not games.com or play.com ?)
SEO.com : $5.000.000 (yess, that is a new and big business)
Altavista.com : $3.300.000 (Compaq paid for it and Altavista was the most popular text search engine before Google comes)
Wine.com : $2.900.000 in end of 1999
Autos.com : $2.200.000 (why not cars.com ?)
Express.com : $1.800.000 : selling music / audio / film / video DVDs
Wallstreet.com: $1.000.000 : in 1999
Rock.com : $1.000.000 related to rock music
Websites.com : $970.000 Verio webhosting/server company using it. (what about web.com or internet.com ?)
Drugs.com : $830.000 in 1999 drugs and medical pharmacy portal