I have ridden every ride (- kiddie rides and WExpress), including a few no longer there. It is possible to do so in one day (did that once), depending on the time of season - early on before the crowds are there, or after the main season and into bonus weekends it would also be possible. And a busy day!
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Po!nt of View: A different look at Roller Coasters.
http://www.crosswinds.net/~justmayntz/thrills/index.html