If you asked me this question a year ago, it would be Cedar point, but I will finally have the pleasure this year of visiting Cedar Point and Ohio, so its not that now. Also I would say SFMM, but again I was very lucky to visit this park in 1994.
So now I would probably say Six Flags Great America and Great Adventure, these 2 six flags parks look awesome, so these are my number 1 top destination now for the future