Well, if we're willing to forgo sticking to ridges the whole way...
The Pacific Northwest Trail. It starts in Glacier National Park and heads west, ending at Cape Alava (westernmost point in CONUS) on the Olympic Peninsula. So you go through the Rockies and Cascades, down to the coast, across Puget Sound, through the Olympic Mountains, to one of the best beach hikes around.
You sort of hit it all. The downside is that you don't walk along ridges very much- you cross them instead. Several times, as you can see in the map. But it is on my life list. (But then, so is the Colorado Trail.)
The guidebook says it takes three months, but I think it was written in non-ultralight style. Author is Ron Strickland. Here is the Pacific Northwest Trail Association website:
EDIT--- Zack- I have no problems with bushwhacking...
But, yeah, the guidebook is from 2001 and mentions a lot of planned improvements. There are areas where the trails aren't well defined (sort of like the CDT) and you just have to navigate your way to the next defined location as best you can. These are usually the lower, forested areas rather than the mountainous ones. Also similar to the CDT, there is occasional road walking (usually near a town). But, again, this is as of 2001. The website will probably say more about it.
PLUS congress just designated it a Nation Scenic Trail in the recent omnibus bill, so presumably it will be improving a bit. (Certainly by the time I can hike it... I.e. retirement.)