I would have to say the anticipated new B&M Flyer at Magic Mountain. Judging by what they have done in the past with building record breaking new coasters, this is sure to be no exception. Eventhough building has not even begun yet, nor do I know what the track layout or some of the elements will be, it is really fascinating to watch as it evolves. Soon the building will start, then I will see the layout. My anticpation building. Eventually, the best part of this whole thing happens, I finally get to ride it! Half a year or so will have gone by from the time I first found out about this to actually seeing it in person and taking my first, very exciting ride on it.
It's one thing to go to a park and see something new there you didn't know about, but quite another to follow something for so long then see it come to fruition- I think it makes it even more enjoyable.