I have to say Carowinds. Might be because it is only 20 minutes from my house and 10 minutes from work.
King's Island definantly has the best woodies around. The Beast is aesome at night. Son of Beast is great in the first 1/2 of the train as the seond 1/2 will bruise you pretty good.
King's Dominion is the prettiest of them (US that is) Volcano, Flight of Fear rule there. They seem to be coming along also
Carowinds just seems to get a new head of steam every year. The park looked brand new this year, the rides were refurbed and fast. Now since Borg has settled in and the paint has worn off the track it too has speeded up a bit. Borg still has some of the probs it had as Stealth but it is not down near what it was in Cali. With almost all of Carowinds attractions many of them were a first which to me makes it pretty cool. They have several different styles and makers of coasters and none are boring. Carowinds only lakes in the hieght and speed areas but wait untill 2006 season. 2005 should be stuff for kids, jrs, families as the rotate every other year between that and thrill rides.